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  • 251.
    Aslandukov, Andrey
    et al.
    University of Bayreuth: Universitat Bayreuth Laboratory of Crystallography, Bayreuth, GERMANY.
    Trybel, Florian
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Aslandukova, Alena
    University of Bayreuth: Universitat Bayreuth Bayerisches Geoinstitut, GERMANY.
    Laniel, Dominique
    The University of Edinburgh Centre for Science at Extreme Conditions and School of Physics and Astronomy, UNITED KINGDOM.
    Fedotenko, Timofey
    DESY: Deutsches Elektronen-Synchrotron Photon Science, Deutsches Elektronen-Synchrotron, GERMANY.
    Khandarkhaeva, Saiana
    University of Bayreuth: Universitat Bayreuth Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, GERMANY.
    Aprilis, Georgios
    ESRF European Synchrotron Radiation Facility, FRANCE.
    Giacobbe, Carlotta
    ESRF European Synchrotron Radiation Facility, FRANCE.
    Lawrence Bright, Eleanor
    ESRF European Synchrotron Radiation Facility, FRANCE.
    Abrikosov, Igor A.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Dubrovinsky, Leonid
    University of Bayreuth: Universitat Bayreuth Bayerisches Geoinstitut, GERMANY.
    Dubrovinskaia, Natalia
    University of Bayreuth: Universitat Bayreuth Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, GERMANY.
    Anionic N18 Macrocycles and a Polynitrogen Double Helix in Novel Yttrium Polynitrides YN6 and Y2N11 at 100 GPa2022In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 61, no 34, article id e202207469Article in journal (Refereed)
    Abstract [en]

    Two novel yttrium nitrides, YN6 and Y2N11, were synthesized by direct reaction between yttrium and nitrogen at 100 GPa and 3000 K in a laser-heated diamond anvil cell. High-pressure synchrotron single-crystal X-ray diffraction revealed that the crystal structures of YN6 and Y2N11 feature a unique organization of nitrogen atoms-a previously unknown anionic N-18 macrocycle and a polynitrogen double helix, respectively. Density functional theory calculations, confirming the dynamical stability of the YN6 and Y2N11 compounds, show an anion-driven metallicity, explaining the unusual bond orders in the polynitrogen units. As the charge state of the polynitrogen double helix in Y2N11 is different from that previously found in Hf2N11 and because N-18 macrocycles have never been predicted or observed, their discovery significantly extends the chemistry of polynitrides.

  • 252. Aslibeiki, B.
    et al.
    Kameli, P.
    Ehsani, M. H.
    Salamati, H.
    Muscas, Giuseppe
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Agostinelli, E.
    Foglietti, V.
    Casciardi, S.
    Peddis, D.
    Solvothermal synthesis of MnFe2O4 nanoparticles: The role of polymer coating on morphology and magnetic properties2016In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 399, p. 236-244Article in journal (Refereed)
  • 253.
    Asp, Leif E.
    et al.
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Bouton, Karl
    Carlstedt, David
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Duan, Shanghong
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Harnden, Ross
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.
    Johannisson, Wilhelm
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.
    Johansen, Marcus
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Lindbergh, Göran
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Liu, Fang
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Peuvot, Kevin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Schneider, Lynn Maria
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.
    Xu, Johanna
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Zenkert, Dan
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.
    A Structural Battery and its Multifunctional Performance2021In: Advanced Energy and Sustainability Research, E-ISSN 2699-9412, Vol. 2, no 3, article id 2000093Article in journal (Refereed)
    Abstract [en]

    Engineering materials that can store electrical energy in structural load paths can revolutionize lightweight design across transport modes. Stiff and strong batteries that use solid-state electrolytes and resilient electrodes and separators are generally lacking. Herein, a structural battery composite with unprecedented multifunctional performance is demonstrated, featuring an energy density of 24 Wh kg−1 and an elastic modulus of 25 GPa and tensile strength exceeding 300 MPa. The structural battery is made from multifunctional constituents, where reinforcing carbon fibers (CFs) act as electrode and current collector. A structural electrolyte is used for load transfer and ion transport and a glass fiber fabric separates the CF electrode from an aluminum foil-supported lithium–iron–phosphate positive electrode. Equipped with these materials, lighter electrical cars, aircraft, and consumer goods can be pursued.

  • 254.
    Aspuru-Guzik, Alan
    et al.
    Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA.;Canadian Inst Adv Res CIFAR, Toronto, ON M5G 1Z8, Canada..
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Uppsala Univ, Theoret Chem Programme, Dept CUppsala Univ, Uppsala Ctr Computat Chem UC3, Box 518, S-75120 Uppsala, Sweden..
    Reiher, Markus
    Swiss Fed Inst Technol, Phys Chem Lab, Vladimir Prelog Weg 2, CH-8093 Zurich, Switzerland..
    The Matter Simulation (R)evolution2018In: ACS CENTRAL SCIENCE, ISSN 2374-7943, Vol. 4, no 2, p. 144-152Article in journal (Refereed)
    Abstract [en]

    To date, the program for the development of methods and models for atomistic and continuum simulation directed toward chemicals and materials has reached an incredible degree of sophistication and maturity. Currently, one can witness an increasingly rapid emergence of advances in computing, artificial intelligence, and robotics. This drives us to consider the future of computer simulation of matter from the molecular to the human length and time scales in a radical way that deliberately dares to go beyond the foreseeable next steps in any given discipline. This perspective article presents a view on this future development that we believe is likely to become a reality during our lifetime.

  • 255. Asres, Georgies Alene
    et al.
    Baldoví, José J.
    Dombovari, Aron
    Järvinen, Topias
    Lorite, Gabriela Simone
    Mohl, Melinda
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Pérez Paz, Alejandro
    Xian, Lede
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Industrial Chemistry & Reaction Engineering, Department of Chemical Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku, Finland.
    Spetz, Anita Lloyd
    Jantunen, Heli
    Rubio, Ángel
    Kordás, Krisztian
    Ultrasensitive H2S gas sensors based on p-type WS2 hybrid materials2018In: Nano Reseach, ISSN 1998-0124, E-ISSN 1998-0000, Vol. 11, no 8, p. 4215-4224Article in journal (Refereed)
    Abstract [en]

    Owing to their higher intrinsic electrical conductivity and chemical stability with respect to their oxide counterparts, nanostructured metal sulfides are expected to revive materials for resistive chemical sensor applications. Herein, we explore the gas sensing behavior of WS2 nanowire-nanoflake hybrid materials and demonstrate their excellent sensitivity (0.043 ppm-1) as well as high selectivity towards H2S relative to CO, NH3, H2, and NO (with corresponding sensitivities of 0.002, 0.0074, 0.0002, and 0.0046 ppm-1, respectively). Gas response measurements, complemented with the results of X-ray photoelectron spectroscopy analysis and first-principles calculations based on density functional theory, suggest that the intrinsic electronic properties of pristine WS2 alone are not sufficient to explain the observed high sensitivity towards H2S. A major role in this behavior is also played by O doping in the S sites of the WS2 lattice. The results of the present study open up new avenues for the use of transition metal disulfide nanomaterials as effective alternatives to metal oxides in future applications for industrial process control, security, and health and environmental safety.

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  • 256.
    Assalauova, Dameli
    et al.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Kim, Young Yong
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Bobkov, Sergey
    Natl Res Ctr, Kurchatov Inst, Akad Kurchatova Pl 1, Moscow 123182, Russia.
    Khubbutdinov, Ruslan
    DESY, Notkestr 85, D-22607 Hamburg, Germany; Natl Res Nucl Univ MEPhI, Moscow Engn Phys Inst, Kashirskoe Sh 31, Moscow 115409, Russia.
    Rose, Max
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Alvarez, Roberto
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA; Arizona State Univ, Sch Math & Stat Sci, Tempe, AZ 85287 USA.
    Andreasson, Jakob
    Acad Sci Czech Republ, ELI Beamlines, Inst Phys, CZ-18221 Prague, Czech Republic.
    Balaur, Eugeniu
    La Trobe Univ, Australian Res Council, La Trobe Inst Mol Sci LIMS, Dept Chem & Phys,Ctr Excellence Adv Mol Imaging, Melbourne, Vic 3086, Australia.
    Contreras, Alice
    Arizona State Univ, Sch Life Sci, Tempe, AZ 85287 USA; Arizona State Univ, Biodesign Inst Ctr Immunotherapy Vaccines & Virot, Tempe, AZ 85287 USA.
    DeMirci, Hasan
    SLAC Natl Accelerator Lab, Stanford Pulse Inst, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA; Koc Univ, Dept Mol Biol & Genet, TR-34450 Istanbul, Turkey.
    Gelisio, Luca
    DESY, Ctr Free Electron Laser Sci CFEL, Notkestr 85, D-22607 Hamburg, Germany.
    Hajdu, Janos
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics. Acad Sci Czech Republ, ELI Beamlines, Inst Phys, CZ-18221 Prague, Czech Republic.
    Hunter, Mark S.
    SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
    Kurta, Ruslan P.
    European XFEL, Holzkoppel 4, D-22869 Schenefeld, Germany.
    Li, Haoyuan
    SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA; Stanford Univ, Phys Dept, 450 Jane Stanford Way, Stanford, CA 94305 USA.
    McFadden, Matthew
    Arizona State Univ, Biodesign Inst Ctr Immunotherapy Vaccines & Virot, Tempe, AZ 85287 USA.
    Nazari, Reza
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA; Arizona State Univ, Sch Engn Matter Transport & Energy, Tempe, AZ 85287 USA.
    Schwander, Peter
    Univ Wisconsin, Milwaukee, WI 53211 USA.
    Teslyuk, Anton
    Natl Res Ctr, Kurchatov Inst, Akad Kurchatova Pl 1, Moscow 123182, Russia; Moscow Inst Phys & Technol, Moscow 141700, Russia.
    Walter, Peter
    SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
    Xavier, P. Lourdu
    DESY, Ctr Free Electron Laser Sci CFEL, Notkestr 85, D-22607 Hamburg, Germany; SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA; Max Planck Inst Struct & Dynam Matter, Luruper Chaussee 149, D-22761 Hamburg, Germany.
    Yoon, Chun Hong
    SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
    Zaare, Sahba
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA; SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
    Ilyin, Viacheslav A.
    Natl Res Ctr, Kurchatov Inst, Akad Kurchatova Pl 1, Moscow 123182, Russia; Moscow Inst Phys & Technol, Moscow 141700, Russia.
    Kirian, Richard A.
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA.
    Hogue, Brenda G.
    Arizona State Univ, Sch Life Sci, Tempe, AZ 85287 USA; Arizona State Univ, Biodesign Inst Ctr Immunotherapy Vaccines & Virot, Tempe, AZ 85287 USA; Arizona State Univ, Ctr Appl Struct Discovery, Biodesign Inst, Tempe, AZ 85287 USA.
    Aquila, Andrew
    SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
    Vartanyants, Ivan A.
    DESY, Notkestr 85, D-22607 Hamburg, Germany; Natl Res Nucl Univ MEPhI, Moscow Engn Phys Inst, Kashirskoe Sh 31, Moscow 115409, Russia.
    An advanced workflow for single-particle imaging with the limited data at an X-ray free-electron laser2020In: IUCrJ, E-ISSN 2052-2525, Vol. 7, p. 1102-1113Article in journal (Refereed)
    Abstract [en]

    An improved analysis for single-particle imaging (SPI) experiments, using the limited data, is presented here. Results are based on a study of bacteriophage PR772 performed at the Atomic, Molecular and Optical Science instrument at the Linac Coherent Light Source as part of the SPI initiative. Existing methods were modified to cope with the shortcomings of the experimental data: inaccessibility of information from half of the detector and a small fraction of single hits. The general SPI analysis workflow was upgraded with the expectation-maximization based classification of diffraction patterns and mode decomposition on the final virus-structure determination step. The presented processing pipeline allowed us to determine the 3D structure of bacteriophage PR772 without symmetry constraints with a spatial resolution of 6.9 nm. The obtained resolution was limited by the scattering intensity during the experiment and the relatively small number of single hits.

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  • 257.
    Assar, Alireza
    et al.
    Tech Univ Denmark, Natl Ctr Nanofabricat & Characterizat, DTU Nanolab, DK-2800 Lyngby, Denmark..
    Martinho, Filipe
    Tech Univ Denmark, Dept Photon Engn, DK-4000 Roskilde, Denmark..
    Larsen, Jes K.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Saini, Nishant
    Uppsala Univ, Dept Mat Sci & Engn, Div Solar Cell Technol, S-75236 Uppsala, Sweden..
    Shearer, Denver
    Tech Univ Denmark, Natl Ctr Nanofabricat & Characterizat, DTU Nanolab, DK-2800 Lyngby, Denmark..
    Moro, Marcos V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Stulen, Fredrik
    Univ Oslo, Dept Phys, N-0371 Oslo, Norway..
    Grini, Sigbjorn
    Univ Oslo, Dept Phys, N-0371 Oslo, Norway..
    Engberg, Sara
    Tech Univ Denmark, Dept Photon Engn, DK-4000 Roskilde, Denmark..
    Stamate, Eugen
    Tech Univ Denmark, Natl Ctr Nanofabricat & Characterizat, DTU Nanolab, DK-2800 Lyngby, Denmark..
    Schou, Jorgen
    Tech Univ Denmark, Dept Photon Engn, DK-4000 Roskilde, Denmark..
    Vines, Lasse
    Univ Oslo, Dept Phys, N-0371 Oslo, Norway..
    Canulescu, Stela
    Tech Univ Denmark, Dept Photon Engn, DK-4000 Roskilde, Denmark..
    Platzer Björkman, Charlotte
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Electrical Engineering, Solid-State Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Hansen, Ole
    Tech Univ Denmark, Natl Ctr Nanofabricat & Characterizat, DTU Nanolab, DK-2800 Lyngby, Denmark..
    Gettering in PolySi/SiOx Passivating Contacts Enables Si-Based Tandem Solar Cells with High Thermal and Contamination Resilience2022In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 14, no 12, p. 14342-14358Article in journal (Refereed)
    Abstract [en]

    Multijunction solar cells in a tandem configuration could further lower the costs of electricity if crystalline Si (c-Si) is used as the bottom cell. However, for direct monolithic integration on c-Si, only a restricted number of top and bottom cell architectures are compatible, due to either epitaxy or high-temperature constraints, where the interface between subcells is subject to a trade-off between transmittance, electrical interconnection, and bottom cell degradation. Using polySi/SiOx passivating contacts for Si, this degradation can be largely circumvented by tuning the polySi/SiOx stacks to promote gettering of contaminants admitted into the Si bottom cell during the top cell synthesis. Applying this concept to the low-cost top cell chalcogenides Cu2ZnSnS4 (CZTS), CuGaSe2 (CGSe), and AgInGaSe2 (AIGSe), fabricated under harsh S or Se atmospheres above 550 degrees C, we show that increasing the heavily doped polySi layer thickness from 40 to up to 400 nm prevents a reduction in Si carrier lifetime by 1 order of magnitude, with final lifetimes above 500 mu s uniformly across areas up to 20 cm(2). In all cases, the increased resilience was correlated with a 99.9% reduction in contaminant concentration in the c-Si bulk, provided by the thick polySi layer, which acts as a buried gettering layer in the tandem structure without compromising the Si passivation quality. The Si resilience decreased as AIGSe > CGSe > CZTS, in accordance with the measured Cu contamination profiles and higher annealing temperatures. An efficiency of up to 7% was achieved for a CZTS/Si tandem, where the Si bottom cell is no longer the limiting factor.

  • 258.
    Atak, Gamze
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. Hacettepe Univ, Dept Phys Engn, TR-06800 Ankara, Turkey.
    Ghorai, Sagar
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Granqvist, Claes G.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Niklasson, Gunnar A.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Bayrak Pehlivan, Ilknur
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Cycling durability and potentiostatic rejuvenation of electrochromic tungsten oxide thin films: Effect of silica nanoparticles in LiClO4-Propylene carbonate electrolytes2023In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 250, article id 112070Article in journal (Refereed)
    Abstract [en]

    Electrochromic (EC) technology allows control of the transmission of visible light and solar radiation through thin-film devices. When applied to “smart” windows, EC technology can significantly diminish energy use for cooling and air conditioning of buildings and simultaneously provide good indoor comfort for the buildings’ occupants through reduced glare. EC “smart” windows are available on the market, but it is nevertheless important that their degradation under operating conditions be better understood and, ideally, prevented. In the present work, we investigated EC properties, voltammetric cycling durability, and potentiostatic rejuvenation of sputter-deposited WO3 thin films immersed in LiClO4–propylene carbonate electrolytes containing up to 3.0 wt% of ∼7-nm-diameter SiO2 nanoparticles. Adding about 1 wt% SiO2 led to a significant improvement in cycling durability in the commonly used potential range of 2.0–4.0 V vs. Li/Li+. Furthermore, X-ray photoemission spectroscopy indicated that O–Si bonds were associated with enhanced durability in the presence of SiO2 nanoparticles.

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  • 259.
    Atakan, Aylin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, Faculty of Science & Engineering.
    Mäkie, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, Faculty of Science & Engineering.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Keraudy, Julien
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Johansson, Emma
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, Faculty of Science & Engineering.
    Odén, Magnus
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, Faculty of Science & Engineering.
    Synthesis of a Cu-infiltrated Zr-doped SBA-15 catalyst for CO2 hydrogenation into methanol and dimethyl ethert2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 29, p. 19139-19149Article in journal (Refereed)
    Abstract [en]

    A catalytically active nanoassembly comprising Cu-nanoparticles grown on integrated and active supports (large pore Zr-doped mesoporous SBA-15 silica) has been synthesized and used to promote CO2 hydrogenation. The doped mesoporous material was synthesized using a sal-gel method, in which the pore size was tuned between 11 and 15 nm while maintaining a specific surface area of about 700 m(2) g (1). The subsequent Cu nanoparticle growth was achieved by an infiltration process involving attachment of different functional groups on the external and internal surfaces of the mesoporous structure such that 7-10 nm sized Cu nanoparticles grew preferentially inside the pores. Chemisorption showed improved absorption of both CO2 and H-2 for the assembly compared to pure SBA-15 and 15% of the total CO2 was converted to methanol and dimethyl ether at 250 degrees C and 33 bar.

  • 260.
    Atif, M.
    et al.
    King Saud Univ, Saudi Arabia.
    Ait Ali, Abderrahman
    COMSATS Inst Informat Technol, Pakistan.
    AlSalhi, M. S.
    King Saud Univ, Saudi Arabia.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics. Linköping University, Faculty of Science & Engineering.
    RETRACTED: Effect of Urea on the Morphology of Fe3O4 Magnetic Nanoparticles and Their Application in Potentiometric Urea Biosensors2019In: Silicon, ISSN 1876-990X, E-ISSN 1876-9918, Vol. 11, no 3, p. 1371-1376Article in journal (Refereed)
    Abstract [en]

    The effect of different concentrations of urea on the morphology of iron oxide (Fe3O4) magnetic nanoparticles was studied. Fe3O4 magnetic nanoparticles were fabricated by the coprecipitation method. The morphology, crystallinity, compositional purity, and emission characteristics were tested by the techniques of scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Raman characterization. The drop-casting technique was successfully used to fabricate a potentiometric urea biosensor producing initially isopropanol and chitosan solution, consisting of Fe3O4 nanoparticles, on a glass fiber filter. To measure the developed biosensors voltage signal from the functionalized nanoparticles, a copper wire was utilized. The Fe3O4 nanoparticle surface functionalization was performed through the electrostatic immobilization of urease with the Fe3O4-chitosan (CH) nanobiocomposite. The presented urea biosensor measured a wide logarithmic range of urea concentration of 0.1-80 mM with a sensitivity of 42 mV/decade, and indicated a fast response time of approximately 12 s. The developed urea biosensor showed enhanced sensitivity, stability, reusability, and specificity. All experimental results demonstrate the application potential of the developed urea sensor for the monitoring of urea concentrations in human serum, drugs, and food industry-related samples.

  • 261.
    Atkins, Duncan
    et al.
    Inst Laue Langevin ILL, 71 Ave Martyrs,CS 20156, F-38042 Grenoble 9, France..
    Ayerbe, Elixabete
    Basque Res & Technol Alliance BRTA, CIDETEC, Paseo Miramon 196, Donostia San Sebastian 20014, Spain..
    Benayad, Anass
    Univ Grenoble Alpes, CEA, Liten, DTNM, F-38045 Grenoble 9, France..
    Capone, Federico G.
    Sorbonne Univ, CNRS, Phys Chim Electrolytes & Nanosyst Interfaciaux, PHENIX, F-75005 Paris, France.;CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France..
    Capria, Ennio
    European Synchrotron Radiat Facil, 71 Ave Martyrs, F-38043 Grenoble, France..
    Castelli, Ivano E.
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark..
    Cekic-Laskovic, Isidora
    Forschungszentrum Julich, IEK 12, Helmholtz Inst Munster, D-48149 Munster, Germany..
    Ciria, Raul
    Basque Res & Technol Alliance BRTA, CIDETEC, Paseo Miramon 196, Donostia San Sebastian 20014, Spain..
    Dudy, Lenart
    Synchrotron SOLEIL, St Aubin BP48, F-91192 Gif Sur Yvette, France..
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Johnson, Mark R.
    Inst Laue Langevin ILL, 71 Ave Martyrs,CS 20156, F-38042 Grenoble 9, France..
    Li, Hongjiao
    Karlsruhe Inst Technol, Inst Nanotechnol, Hermann von Helmholtz Platz 1, D-76344 Karlsruhe, Germany..
    Garcia Lastra, Juan Maria
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark..
    Leal De Souza, Matheus
    CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France.;Univ Picardie Jules Verne, CNRS, UMR 7314, Lab React & Chim Solides LRCS,HUB Energie, 15 Rue Baudelocque, F-80039 Amiens, France..
    Meunier, Valentin
    CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France.;Coll France, UMR 8260, Chim Solide & Energie, F-75231 Paris 05, France..
    Morcrette, Mathieu
    CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France..
    Reichert, Harald
    European Synchrotron Radiat Facil, 71 Ave Martyrs, F-38043 Grenoble, France..
    Simon, Patrice
    CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France.;Univ Toulouse III Paul Sabatier, Lab CIRIMAT, CNRS, UMR 5085, 118 Route Narbonne, F-31062 Toulouse, France..
    Rueff, Jean-Pascal
    Synchrotron SOLEIL, St Aubin BP48, F-91192 Gif Sur Yvette, France.;Sorbonne Univ, CNRS, Lab Chim Phys Matiere & Rayonnement, F-75005 Paris, France..
    Sottmann, Jonas
    Sorbonne Univ, CNRS, Phys Chim Electrolytes & Nanosyst Interfaciaux, PHENIX, F-75005 Paris, France.;CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France..
    Wenzel, Wolfgang
    Karlsruhe Inst Technol, Inst Nanotechnol, Hermann von Helmholtz Platz 1, D-76344 Karlsruhe, Germany.;Univ Picardie Jules Verne, CNRS, UMR 7314, Lab React & Chim Solides LRCS,HUB Energie, 15 Rue Baudelocque, F-80039 Amiens, France..
    Grimaud, Alexis
    CNRS, FR 3459, Reseau Stockage Electrochim Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France.;Coll France, UMR 8260, Chim Solide & Energie, F-75231 Paris 05, France..
    Understanding Battery Interfaces by Combined Characterization and Simulation Approaches: Challenges and Perspectives2022In: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 12, no 17, article id 2102687Article, review/survey (Refereed)
    Abstract [en]

    Driven by the continuous search for improving performances, understanding the phenomena at the electrode/electrolyte interfaces has become an overriding factor for the success of sustainable and efficient battery technologies for mobile and stationary applications. Toward this goal, rapid advances have been made regarding simulations/modeling techniques and characterization approaches, including high-throughput electrochemical measurements coupled with spectroscopies. Focusing on Li-ion batteries, current developments are analyzed in the field as well as future challenges in order to gain a full description of interfacial processes across multiple length/timescales; from charge transfer to migration/diffusion properties and interphases formation, up to and including their stability over the entire battery lifetime. For such complex and interrelated phenomena, developing a unified workflow intimately combining the ensemble of these techniques will be critical to unlocking their full investigative potential. For this paradigm shift in battery design to become reality, it necessitates the implementation of research standards and protocols, underlining the importance of a concerted approach across the community. With this in mind, major collaborative initiatives gathering complementary strengths and skills will be fundamental if societal and environmental imperatives in this domain are to be met.

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  • 262.
    Atkins, Duncan
    et al.
    Inst Laue Langevin ILL, BP 156,71 Ave Martyrs, F-38042 Grenoble, France..
    Capria, Ennio
    European Synchrotron Radiat Facil ESRF, CS 40220,71 Ave Martyrs, F-38043 Grenoble, France..
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Famprikis, Theodosios
    Delft Univ Technol, Dept Radiat Sci & Technol, Mekelweg 15, NL-2629 JB Delft, Netherlands..
    Grimaud, Alexis
    Coll France, Chim Solide & Energie, UMR 8260, F-75231 Paris 5, France.;CNRS FR 3459, Reseau Stockage Elect Energie RS2E, 33 Rue St Leu, F-80039 Amiens, France..
    Jacquet, Quentin
    Univ Grenoble Alpes, IRIGSyMMES, CEA, CNRS, F-38000 Grenoble, France..
    Johnson, Mark
    Inst Laue Langevin ILL, BP 156,71 Ave Martyrs, F-38042 Grenoble, France..
    Matic, Aleksandar
    Chalmers Univ Technol, Dept Phys, S-41296 Gothenburg, Sweden..
    Norby, Poul
    Tech Univ Denmark, DK-2800 Lyngby, Denmark..
    Reichert, Harald
    European Synchrotron Radiat Facil ESRF, CS 40220,71 Ave Martyrs, F-38043 Grenoble, France..
    Rueff, Jean-Pascal
    LOrme Merisiers, Synchrotron SOLEIL, BP 48 Saint Aubin, F-91192 Gif Sur Yvette, France.;Sorbonne Univ, CNRS, Lab Chim Phys Matiere & Rayonnement, F-75005 Paris, France..
    Villevieille, Claire
    Univ Grenoble Alpes, IRIGSyMMES, CEA, CNRS, F-38000 Grenoble, France..
    Wagemaker, Marnix
    Delft Univ Technol, Dept Radiat Sci & Technol, Mekelweg 15, NL-2629 JB Delft, Netherlands..
    Lyonnard, Sandrine
    Univ Grenoble Alpes, IRIGSyMMES, CEA, CNRS, F-38000 Grenoble, France..
    Accelerating Battery Characterization Using Neutron and Synchrotron Techniques: Toward a Multi-Modal and Multi-Scale Standardized Experimental Workflow2022In: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 12, no 17, article id 2102694Article in journal (Refereed)
    Abstract [en]

    Li-ion batteries are the essential energy-storage building blocks of modern society. However, producing ultra-high electrochemical performance in safe and sustainable batteries for example, e-mobility, and portable and stationary applications, demands overcoming major technological challenges. Materials engineering and new chemistries are key aspects to achieving this objective, intimately linked to the use of advanced characterization techniques. In particular, operando investigations are currently attracting enormous interest. Synchrotron- and neutron-based bulk techniques are increasingly employed as they provide unique insights into the chemical, morphological, and structural changes inside electrodes and electrolytes across multiple length scales with high time/spatial resolutions. However, data acquisition, data analysis, and scientific outcomes must be accelerated to increase the overall benefits to the academic and industrial communities, requiring a paradigm shift beyond traditional single-shot, sophisticated experiments. Here a multi-scale and multi-technique integrated workflow is presented to enhance bulk characterization, based on standardized and automated data acquisition and analysis for high-throughput and high-fidelity experiments, the optimization of versatile and tunable cells, as well as multi-modal correlative characterization. Furthermore, new mechanisms, methods and organizations such as artificial intelligence-aided modeling-driven strategies, coordinated beamtime allocations, and community-unified infrastructures are discussed in order to highlight perspectives in battery research at large scale facilities.

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  • 263. Atluri, Rambabu
    et al.
    Iqbal, Muhammad Naeem
    Bacsik, Zoltan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Materials Chemistry.
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Villaescusa, Luis Angel
    Garcia-Bennett, Alfonso E.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry. alfonso@mmk.su.se.
    Self-Assembly Mechanism of Folate-Templated Mesoporous Silica2013In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, no 38, p. 12003-12012Article in journal (Refereed)
    Abstract [en]

    A method to form ordered mesoporous silica based on the use of folate supramolecular templates has been developed. Evidence based on in situ small-angle X-ray scattering (SAXS), electron microscopy, infrared spectroscopy, and in situ conductivity measurements are used to investigate the organic inorganic interactions and synthesis mechanism. The behavior of folate molecules in solution differs distinctively from that of surfactants commonly used for the preparation of ordered mesoporous silica phases, notably with the absence of a critical micellar concentration. In situ SAXS studies reveal fluctuations in X-ray scattering intensities consistent with the condensation of the silica precursor surrounding the folate template and the growth of the silica mesostructure in the initial stages. High-angle X-ray diffraction shows that the folate template is well-ordered within the pores even after a few minutes of synthesis. Direct structural data for the self-assembly of folates into chiral tetramers within the pores of mesoporous silica provide evidence for the in register stacking of folate tetramers, resulting in a chiral surface of rotated tetramers, with a rotation angle of 30 degrees. Additionally, the self-assembled folates within pores were capable of adsorbing a considerable amount of CO2 gas through the cavity space of the tetramers. The study demonstrates the validity of using a naturally occurring template to produce relevant and functional mesoporous materials.

  • 264.
    Atoufi Najafabadi, Zhaleh
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Development and Tailoring of Low‐Density Cellulose‐Based Structures for Water Treatment2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The challenges posed by our limited clean water sources and the well-known global water pollution demand more efficient water purification technologies. Additionally, the increasing environmental awareness has inspired a shift towards eco-friendly and renewable materials and technologies. This thesis is focused on developing effective adsorbent materials from renewable resources to eliminate organic solvents, dyes, and metal ions from water. Cellulose, the most abundant biopolymer in nature, is the main component used to develop new materials in the present study. Its distinctive physical and colloidal properties, in the form of nanocellulose, along with tunable surface chemistry, play key roles in enhancing the effectiveness of the developed materials.

    The primary focus of the first part of the thesis was to develop a molecular layer-by-layer modification technique to customize the surface functionality of cellulose aerogels in a uniform and controlled manner. Through the sequential deposition of diamine and triacid monomers, exceeding lythin polyamide coatings were formed on the cellulose aerogels, altering the surface properties from hydrophilic to hydrophobic. This transformation made them well-suited structures for oil-water separation.

    Following this, a biohybrid aerogel was developed based on cellulose nanofibrils (CNFs) and amyloid nanofibrils (ANFs), the latter derived by heat treatment of β-lactoglobulin proteins. The pH-tunable surface charge of the aerogel, controlled by the amphiphilicity of the protein, allowed for the adsorption of both cationic and anionic contaminants by adjusting the pH of the solutions. Furthermore, the aerogels exhibited remarkable selectivity for lead (II) ions and they could also be regenerated and reused after each adsorption cycle without a significant loss of their adsorption capacity. This was to a large extent possible due to the excellent wet stability of these aerogels, which was achieved by crosslinking the CNFs during freezing and ice templating, eliminating the need for freeze-drying. However, a solvent exchange to acetone after melting was still necessary to reduce the influence of the capillary forces during drying to avoid the collapse of the aerogels. In a consecutive study, the foaming characteristics of the heat-treated β-lactoglobulin system were exploited to create highly stable Pickering foams with the aid of using CNFs as stabilizers and to physically lock the system through a controlled pH reduction. Interestingly, these Pickering foams could be directly oven-dried without collapsing, yielding low-density foams. Furthermore, it was demonstrated that the foams can be chemically crosslinked by incorporating chemical crosslinkers in the formulation or by pre-functionalizing the CNFs with dialdehydes. This crosslinking naturally also provided wet stability to the oven-dried foams.

    Finally, an innovative and environmentally friendly method was introduced to increase the charge of cellulose fibers by radical polymerization of acrylic acid from the fibers, enabling the preparation of fibers with an exceptionally high charge of 6.7 mmol/g. The introduction of these charged groups significantly enhanced the interaction of the fibers with methylene blue as a model dye and lead (II), Copper (II), and Zinc (II) ions as model metal ions, showing the huge potential of these fibers as building blocks for a wide range of adsorbent applications. Overall, this thesis demonstrates the development and characterization of several bio-based adsorbents for water remediation.

  • 265.
    Atoufi, Zhaleh
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Ciftci, Göksu Cinar
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Reid, Michael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Larsson, Per A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wågberg, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Green Ambient-Dried Aerogels with a Facile pH-Tunable Surface Charge for Adsorption of Cationic and Anionic Contaminants with High Selectivity2022In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 23, no 11, p. 4934-4947Article in journal (Refereed)
    Abstract [en]

    The fabrication of reusable, sustainable adsorbents from low-cost, renewable resources via energy efficient methods is challenging. This paper presents wet-stable, carboxymethylated cellulose nanofibril (CNF) and amyloid nanofibril (ANF) based aerogel-like adsorbents prepared through efficient and green processes for the removal of metal ions and dyes from water. The aerogels exhibit tunable densities (18-28 kg m-3), wet resilience, and an interconnected porous structure (99% porosity), with a pH controllable surface charge for adsorption of both cationic (methylene blue and Pb(II)) and anionic (brilliant blue, congo red, and Cr(VI)) model contaminants. The Langmuir saturation adsorption capacity of the aerogel was calculated to be 68, 79, and 42 mg g-1for brilliant blue, Pb(II), and Cr(VI), respectively. Adsorption kinetic studies for the adsorption of brilliant blue as a model contaminant demonstrated that a pseudo-second-order model best fitted the experimental data and that an intraparticle diffusion model suggests that there are three adsorption stages in the adsorption of brilliant blue on the aerogel. Following three cycles of adsorption and regeneration, the aerogels maintained nearly 97 and 96% of their adsorption capacity for methylene blue and Pb(II) as cationic contaminants and 89 and 80% for brilliant blue and Cr(VI) as anionic contaminants. Moreover, the aerogels showed remarkable selectivity for Pb(II) in the presence of calcium and magnesium as background ions, with a selectivity coefficient more than 2 orders of magnitude higher than calcium and magnesium. Overall, the energy-efficient and sustainable fabrication procedure, along with good structural stability, reusability, and selectivity, makes these aerogels very promising for water purification applications.

  • 266.
    Atoufi, Zhaleh
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Gordeyeva, Korneliya
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fiberprocesser.
    Cortes Ruiz, Maria F.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Hall, Stephen A
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics, Solid Mechanics.
    Larsson, Per A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Wågberg, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Wet-resilient foams based on heat-treated β-lactoglobulin and cellulose nanofibrilsManuscript (preprint) (Other academic)
  • 267.
    Atoufi, Zhaleh
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Gordeyeva, Korneliya
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fiberprocesser.
    Cortes Ruiz, Maria F.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Larsson, Per A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Wågberg, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Synergistically stabilized wet foams from heat treated β-lactoglobulin and cellulose nanofibrils and their application for green foam productionManuscript (preprint) (Other academic)
  • 268.
    Atoufi, Zhaleh
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Reid, Michael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Larsson, Per A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Wågberg, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Surface tailoring of cellulose aerogel-like structures with ultrathin coatings using molecular layer-by-layer assembly2022In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 282, article id 119098Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibril-based aerogels have promising applicability in various fields; however, developing an effi-cient technique to functionalize and tune their surface properties is challenging. In this study, physically and covalently crosslinked cellulose nanofibril-based aerogel-like structures were prepared and modified by a mo-lecular layer-by-layer (m-LBL) deposition method. Following three m-LBL depositions, an ultrathin polyamide layer was formed throughout the aerogel and its structure and chemical composition was studied in detail. Analysis of model cellulose surfaces showed that the thickness of the deposited layer after three m-LBLs was approximately 1 nm. Although the deposited layer was extremely thin, it led to a 2.6-fold increase in the wet specific modulus, improved the acid-base resistance, and changed the aerogels from hydrophilic to hydrophobic making them suitable materials for oil absorption with the absorption capacity of 16-36 g/g. Thus, demon-strating m-LBL assembly is a powerful technique for tailoring surface properties and functionality of cellulose substrates.

  • 269.
    Attarzadeh, Reza
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Attarzadeh-Niaki, Seyed-Hosein
    Shahid Beheshti Univ SBU, Fac Comp Sci & Engn, Tehran, Iran..
    Duwig, Christophe
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology.
    Multi-objective optimization of TPMS-based heat exchangers for low-temperature waste heat recovery2022In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 212, p. 118448-, article id 118448Article in journal (Refereed)
    Abstract [en]

    The transformation to a truly sustainable energy system will require taking better advantage of the waste heat. Integrating heat exchangers with the triply periodic minimal surface (TPMS) is a promising and efficient way to build waste heat recovery systems that harness heat emissions from the low pitch thermal systems. This is mainly due to the low hydrodynamic resistance and pressure drop in the TPMS while securing good heat transfer at low-temperature gradient. This study establishes a computational design and analysis of heat and mass transfer inside a heat exchanger based on the TPMS structure and determine thermal effectiveness, heat transfer coefficient, and pressure drop inside the channel. The non-linearity dependence of results to several design variables makes obtaining the optimal design configuration solely using conventional CFD or experimental study nearly impossible. Hence, a multi-objective optimization workflow based on a Genetic Algorithm for laminar flow is employed to reveal the underlying relationships between design variables for the optimal configurations. The results illustrate the local sensitivity of important parameters such as the heat transfer coefficient, Nusselt number, and thermal performance of the heat exchanger against various design variables. It is shown that the pressure drop is directly affected by gas inlet velocity, viscosity, and density, from high to low, respectively. The Pareto frontiers for the optimal thermal performance are extracted, and the correlation between design objectives is determined. This methodology provides a promising framework for heat exchangers' design analysis, including multi-objective goals and design constraints.

  • 270.
    Attia, Nour F.
    et al.
    Natl Inst Stand, Chem Div, Giza 12211, Egypt..
    Abd El-Monaem, Eman M.
    Alexandria Univ, Fac Sci, Chem Dept, Alexandria, Egypt..
    El-Aqapa, Hisham G.
    Alexandria Univ, Fac Sci, Chem Dept, Alexandria, Egypt..
    Elashery, Sally E. A.
    Cairo Univ, Fac Sci, Chem Dept, Gamaa Str, Giza 12613, Egypt..
    Eltaweil, Abdelazeem S.
    Alexandria Univ, Fac Sci, Chem Dept, Alexandria, Egypt..
    El Kady, Misara
    Ain Shams Univ, Fac Sci, Chem Dept, Cairo, Egypt..
    Khalifa, Shaden A. M.
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden..
    Hawash, Hamada B.
    Natl Inst Oceanog & Fisheries NIOF, Environm Div, Alexandria, Egypt..
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Menoufia Univ, Fac Sci, Dept Chem, Shibin Al Kawm 32512, Egypt; Jiangsu Univ, Int Res Ctr Food Nutr & Safety, Zhenjiang 212013, Jiangsu, Peoples R China.
    Iron oxide nanoparticles and their pharmaceutical applications2022In: Applied Surface Science Advances, E-ISSN 2666-5239, Vol. 11, article id 100284Article in journal (Refereed)
    Abstract [en]

    The importance of different polymorphic forms of iron oxide nanoparticles attracted a lot of attentions in various applications due to their unique electrical, optical and magnetic properties. Moreover, the excellent biocompatibility, high surface area, spherical shape, tunable nanoscale size and the availability of synthesis route make them desirable in various biological and pharmaceutical applications. To this aim, in this review, different synthesis methods of iron oxide nanoparticles were discussed, also the main characterization techniques used for elucidation of the iron oxide nanoparticles were reviewed. The exploitation of iron oxide nanoparticles-based systems as anticancer, antiviral, antimicrobial agents and its involvement in drug delivery system were reviewed in details. Additionally, the influence of nanoparticles size and the reagent type and conditions utilized in synthesis and their pharmaceutical applications was highlighted.

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  • 271.
    Aulin, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
    Extracellular Matrix Based Materials for Tissue Engineering2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The extracellular matrix is (ECM) is a network of large, structural proteins and polysaccharides, important for cellular behavior, tissue development and maintenance. Present thesis describes work exploring ECM as scaffolds for tissue engineering by manipulating cells cultured in vitro or by influencing ECM expression in vivo. By culturing cells on polymer meshes under dynamic culture conditions, deposition of a complex ECM could be achieved, but with low yields. Since the major part of synthesized ECM diffused into the medium the rate limiting step of deposition was investigated. This quantitative analysis showed that the real rate limiting factor is the low proportion of new proteins which are deposited as functional ECM. It is suggested that cells are pre-embedded in for example collagen gels to increase the steric retention and hence functional deposition.

    The possibility to induce endogenous ECM formation and tissue regeneration by implantation of growth factors in a carrier material was investigated. Bone morphogenetic protein-2 (BMP-2) is a growth factor known to be involved in growth and differentiation of bone and cartilage tissue. The BMP-2 processing and secretion was examined in two cell systems representing endochondral (chondrocytes) and intramembranous (mesenchymal stem cells) bone formation. It was discovered that chondrocytes are more efficient in producing BMP-2 compared to MSC. The role of the antagonist noggin was also investigated and was found to affect the stability of BMP-2 and modulate its effect. Finally, an injectable gel of the ECM component hyaluronan has been evaluated as delivery vehicle in cartilage regeneration. The hyaluronan hydrogel system showed promising results as a versatile biomaterial for cartilage regeneration, could easily be placed intraarticulary and can be used for both cell based and cell free therapies.

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  • 272. Aung, S. H.
    et al.
    Zhao, L.
    Nonomura, K.
    Oo, T. Z.
    Zakeeruddin, S. M.
    Vlachopoulos, N.
    Sloboda, Tamara
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Svanström, S.
    Cappel, Ute B.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Hagfeldt, A.
    Grätzel, M.
    Toward an alternative approach for the preparation of low-temperature titanium dioxide blocking underlayers for perovskite solar cells2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 17, p. 10729-10738Article in journal (Refereed)
    Abstract [en]

    The anodic electrodeposition method is investigated as an alternative technique for the preparation of a titanium oxide (TiO 2 ) blocking underlayer (UL) for perovskite solar cells (PSCs). Extremely thin Ti IV -based films are grown from aqueous acidic titanium(iii) chloride in an electrochemical cell at room temperature. This precursor layer is converted to the UL (ED-UL), in a suitable state for PSC applications, by undertaking a sintering step at 450 °C for half an hour. PSCs with the composition of the light-absorbing material FA 0.85 MA 0.10 Cs 0.05 Pb(I 0.87 Br 0.13 ) 3 (FA and MA denote the formamidinium and methylammonium cations, respectively) based on the ED-UL are compared with PSCs with the UL of a standard type prepared by the spray-pyrolysis method at 450 °C from titanium diisopropoxide bis(acetylacetonate) (SP-UL). We obtain power conversion efficiencies (PCEs) of over 20% for mesoscopic perovskite devices employing both ED-ULs and SP-ULs. Slightly higher fill factor values are observed for ED-UL-based devices. In addition, ED-ULs prepared by the same method have also been applied in planar PSCs, resulting in a PCE exceeding 17%, which is comparable to that for similar PSCs with an SP-UL. The preparation of ED-ULs with a lower sintering temperature, 150 °C, has also been examined. The efficiency of a planar PSC incorporating this underlayer was 14%. These results point out to the possibility of applying ED-ULs in flexible planar PSCs in the future.

  • 273.
    Aung, Soe Ko Ko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Sakon Nakhon Rajabhat Univ, Res & Dev Inst, Ctr Excellence Alternat Energy, Dept Phys, Fac Sci & Technol, Opt Res Lab, Sakon Nakhon 47000, Thailand.
    Vijayan, Anuja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Seetawan, Tosawat
    Sakon Nakhon Rajabhat Univ, Res & Dev Inst, Ctr Excellence Alternat Energy, Dept Phys,Fac Sci & Technol,Opt Res Lab, Sakon Nakhon 47000, Thailand..
    Enhanced Thermal Stability of Low-Temperature Processed Carbon-Based Perovskite Solar Cells by a Combined Antisolvent/Polymer Deposition Method2022In: Energy Technology, ISSN 2194-4288, Vol. 10, no 8, article id 2200177Article in journal (Refereed)
    Abstract [en]

    Low-temperature processed carbon-based perovskite solar cells have received great attention due to low-cost, high stability, and simple preparation processes that can be employed in large-scale manufacturing. Carbon paste is deposited by techniques such as doctor blading or screen printing. However, solvents from this paste can damage the perovskite or underlying layers resulting in poor performance of solar cells. Furthermore, carbon is not an ideal hole-selective contact. To overcome these issues, the antisolvent treatment is combined with the deposition of a polymeric hole conductor. Specifically, poly(3-hexylthiophene) (P3HT), added into the chlorobenzene antisolvent, improves perovskite morphology and reduces interfacial carrier recombination. As a result, the power conversion efficiency (PCE) of solar cells with the device structure SnO2/MAPbI3/P3HT/carbon increases to 12.16% from 10.6% of pristine devices without P3HT, using pure antisolvent. For poly(triarylamine) hole conductor in the same method, PCE improves only slightly to 11.1%. After 260 h of thermal stress at 82 °C, the P3HT-additive devices improve PCE up to 13.2% in air and maintain 91% of their initial efficiency over 800 h.

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  • 274.
    Aung, Soe Ko Ko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Sakon Nakhon Rajabhat Univ, Res & Dev Inst, Fac Sci & Technol, Ctr Excellence Alternat Energy,Dept Phys,Opt Res L, Sakon Nakhon 47000, Thailand..
    Vijayan, Anuja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Karimipour, Masoud
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Catalan Inst Nanosci & Nanotechnol ICN2, CSIC, Bldg ICN2,Campus UAB, E-08193 Bellaterra, Barcelona, Spain.;Barcelona Inst Sci & Technol BIST, Bldg ICN2,Campus UAB, E-08193 Bellaterra, Barcelona, Spain.;Vali E Asr Univ Rafsanjan, Fac Sci, Dept Phys, Rafsanjan 77139-36417, Iran..
    Seetawan, Tosawat
    Sakon Nakhon Rajabhat Univ, Res & Dev Inst, Fac Sci & Technol, Ctr Excellence Alternat Energy,Dept Phys,Opt Res L, Sakon Nakhon 47000, Thailand..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Reduced hysteresis and enhanced air stability of low-temperature processed carbon-based perovskite solar cells by surface modification2023In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 443, article id 141935Article in journal (Refereed)
    Abstract [en]

    Low temperature processed carbon-based perovskite solar cells (C-PSCs) have gained great interest because of low cost and ease of fabrication. By replacing the Au electrode with carbon, stable solar cells suited for mass-production process can be made. However, power conversion efficiencies (PCEs) of C-PSCs still lag behind that of PSCs with Au contact.Here we explore low temperature (<= 150 degrees C) processed C-PSCs with, where a two-step method is used to prepare mixed-ion lead perovskite films, with tin oxide (SnO2) electron transport layer, poly(3-hexylthiophene-2,5-diyl) (P3HT) hole transport layer and carbon electrode, resulting in devices with a PCE of 14.0%. Moreover, hexyl trimethylammonium bromide (HTAB) was introduced to improve the interface between perovskite and P3HT. Perovskite grains were remarkably enlarged into micrometer-size and defects were reduced. As a result, a champion PCE of 16.1% was obtained, mainly due to enhanced fill factor from 0.67 to 0.73. The interface modification by HTAB molecule is an effective way to passivate the perovskite defects and facilitate the carrier transport at the perovskite/HTL interface. Unencapsulated devices showed excellent stability over 1500 h stored under ambient air (relative humidity -50 +/- 10%).

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  • 275.
    Aung, Soe Ko Ko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Sakon Nakhon Rajabhat Univ, Dept Phys, Fac Sci & Technol, Opt Res Lab,Ctr Excellence Alternat Energy,Res &, Sakon Nakhon 47000, Thailand.23, SE-75120 Uppsala, Sweden..
    Vijayan, Anuja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Seetawan, Tosawat
    Sakon Nakhon Rajabhat Univ, Dept Phys, Fac Sci & Technol, Opt Res Lab,Ctr Excellence Alternat Energy,Res &, Sakon Nakhon 47000, Thailand..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Improved Efficiency of Perovskite Solar Cells with Low-Temperature-Processed Carbon by Introduction of a Doping-Free Polymeric Hole Conductor2022In: Solar RRL, E-ISSN 2367-198X, Vol. 6, no 8, article id 2100773Article in journal (Refereed)
    Abstract [en]

    Low-temperature-processed carbon-based perovskite solar cells (C-PSCs) are promising photovoltaic devices, because of their good stability, low cost, and simple preparation methods, which allow for scalable processing. Herein, C-PSCs with the n-i-p structure are prepared, using a SnO2 nanoparticles film as the electron-selective contact, MAPbI(3) perovskite as the intrinsic absorber layer (MA = methylammonium), and a carbon layer as the hole-selective layer and conductor. Carbon is, however, not an ideal hole-selective layer and it is found that improved solar cell performance can be obtained by introducing a polymeric hole conductor between the perovskite and the carbon layer. Specifically, undoped poly(3-hexylthiophene) (P3HT) is used for this purpose, as it is stable and highly hydrophobic. For ITO/SnO2/MAPbI(3)/carbon devices, a solar cell efficiency of up to 12.8% is obtained, increasing up to 15.7% with the inclusion of a P3HT layer, which increases open-circuit potential, photocurrent, and fill factor (FF). In comparison, ITO/SnO2/MAPbI(3)/P3HT/Au devices performed rather poorly (up to 11.7%). Encouraging stability is obtained for unencapsulated C-PSC devices: P3HT/carbon devices do not show any degradation in solar cell performance upon storage for 1 month in low humidity, while they maintain 70% of their initial efficiency after 900 h at 82 degrees C in air.

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  • 276.
    Aung, Su Htike
    et al.
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland;Shwebo Univ, Phys Dept, Shwebo 02261, Myanmar;Univ Mandalay, Dept Phys, Mat Res Lab, Mandalay 05032, Myanmar.
    Zhao, Lichen
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland;Peking Univ, Dept Phys, State Key Lab Artificial Microstruct & Mesoscop P, Beijing 100871, Peoples R China.
    Nonomura, Kazuteru
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Oo, Than Zaw
    Univ Mandalay, Dept Phys, Mat Res Lab, Mandalay 05032, Myanmar.
    Zakeeruddin, Shaik M.
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Vlachopoulos, Nick
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Sloboda, Tamara
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Svanström, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Cappel, Ute B.
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Hagfeldt, Anders
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Graetzel, Michael
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Toward an alternative approach for the preparation of low-temperature titanium dioxide blocking underlayers for perovskite solar cells2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 17, p. 10729-10738Article in journal (Refereed)
    Abstract [en]

    The anodic electrodeposition method is investigated as an alternative technique for the preparation of a titanium oxide (TiO2) blocking underlayer (UL) for perovskite solar cells (PSCs). Extremely thin Ti-IV-based films are grown from aqueous acidic titanium(III) chloride in an electrochemical cell at room temperature. This precursor layer is converted to the UL (ED-UL), in a suitable state for PSC applications, by undertaking a sintering step at 450 degrees C for half an hour. PSCs with the composition of the light-absorbing material FA(0.85)MA(0.10)Cs(0.05)Pb(I0.87Br0.13)(3) (FA and MA denote the formamidinium and methylammonium cations, respectively) based on the ED-UL are compared with PSCs with the UL of a standard type prepared by the spray-pyrolysis method at 450 degrees C from titanium diisopropoxide bis(acetylacetonate) (SP-UL). We obtain power conversion efficiencies (PCEs) of over 20% for mesoscopic perovskite devices employing both ED-ULs and SP-ULs. Slightly higher fill factor values are observed for ED-UL-based devices. In addition, ED-ULs prepared by the same method have also been applied in planar PSCs, resulting in a PCE exceeding 17%, which is comparable to that for similar PSCs with an SP-UL. The preparation of ED-ULs with a lower sintering temperature, 150 degrees C, has also been examined. The efficiency of a planar PSC incorporating this underlayer was 14%. These results point out to the possibility of applying ED-ULs in flexible planar PSCs in the future.

  • 277.
    Auroux, Etienne
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Huseynova, Gunel
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ràfols-Ribé, Joan
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Miranda la Hera, Vladimir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics.
    A metal-free and transparent light-emitting device by sequential spray-coating fabrication of all layers including PEDOT:PSS for both electrodes2023In: RSC Advances, E-ISSN 2046-2069, Vol. 13, no 25, p. 16943-16951Article in journal (Refereed)
    Abstract [en]

    The concept of a metal-free and all-organic electroluminescent device is appealing from both sustainability and cost perspectives. Herein, we report the design and fabrication of such a light-emitting electrochemical cell (LEC), comprising a blend of an emissive semiconducting polymer and an ionic liquid as the active material sandwiched between two poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) conducting-polymer electrodes. In the off-state, this all-organic LEC is highly transparent, and in the on-state, it delivers uniform and fast to turn-on bright surface emission. It is notable that all three device layers were fabricated by material- and cost-efficient spray-coating under ambient air. For the electrodes, we systematically investigated and developed a large number of PEDOT:PSS formulations. We call particular attention to one such p-type doped PEDOT:PSS formulation that was demonstrated to function as the negative cathode, as well as future attempts towards all-organic LECs to carefully consider the effects of electrochemical doping of the electrode in order to achieve optimum device performance.

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  • 278.
    Auroux, Etienne
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sandström, Andreas
    LunaLEC AB, Umeå, Sweden.
    Larsen, Christian
    Umeå University, Faculty of Science and Technology, Department of Physics. LunaLEC AB, Umeå, Sweden.
    Zäll, Erik
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Lundberg, Petter
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics. LunaLEC AB, Umeå, Sweden.
    Evidence and Effects of Ion Transfer at Active-Material/Electrode Interfaces in Solution-Fabricated Light-Emitting Electrochemical Cells2021In: Advanced Electronic Materials, E-ISSN 2199-160X, Vol. 7, no 8, article id 2100253Article in journal (Refereed)
    Abstract [en]

    The light-emitting electrochemical cell (LEC) allows for energy- and cost-efficient printing and coating fabrication of its entire device structure, including both electrodes and the single-layer active material. This attractive fabrication opportunity is enabled by the electrochemical action of mobile ions in the active material. However, a related and up to now overlooked issue is that such solution-fabricated LECs commonly comprise electrode/active-material interfaces that are open for transfer of the mobile ions, and it is herein demonstrated that a majority of the mobile anions in a common spray-coated active material can transfer into a spray-coated poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) positive electrode during LEC operation. Since it is well established that the mobile ion concentration in the active material has a profound influence on the LEC performance, this significant ion transfer is an important factor that should be considered in the design of low-cost LEC devices that deliver high performance.

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  • 279. Aveyard,, J
    et al.
    Hajne, J.
    Månsson, Alf
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Persson, Malin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    van Delft,, F.C.M.J.M.
    van Zijl, J.
    Snijder, J.
    van den Heuvel,, F.C.
    Nicolau,, D.V.
    Actin motility confinement on micro/nanostructured surfaces.2013In: Proc. SPI 8587, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI, 858722 (February 22, 2013) / [ed] Daniel L. Farkas; Dan V. Nicolau; Robert C. Leif, SPIE - International Society for Optical Engineering, 2013, p. 858722-858727Conference paper (Refereed)
  • 280. Avila, M.
    et al.
    Burks, T.
    Akhtar, Farid
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Gothelid, M.
    Lansaker, P. C.
    Toprak, M. S.
    Muhammed, M.
    Uheida, A.
    Surface functionalized nanofibers for the removal of chromium(VI) from aqueous solutions2014In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 245, p. 201-209Article in journal (Refereed)
    Abstract [en]

    Polyacrylonitrile (PAN) nanofibers functionalized with amine groups (PAN-NH2) were prepared using a simple one-step reaction route. The PAN-NH2 nanofibers were investigated for the removal of chromium(VI) from aqueous solutions. The adsorption and the kinetic characteristics were evaluated in batch process. The adsorption process showed pH dependence and the maximum Cr(VI) adsorption occurred at pH = 2. The Langmuir adsorption model described well the experimental adsorption data and estimated a maximum loading capacity of 156 mg/g, which is a markedly high value compared to other adsorbents reported. The kinetics studies indicated that the equilibrium was attained after 90 min and the experimental data followed a pseudo-second order model suggesting a chemisorption process as the rate limiting step. X-ray Photoelectron Spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) revealed that the adsorption of Cr(VI) species on PAN-NH2 was facilitated through both electrostatic attraction and surface complexation. High desorption efficiency (> 90%) of Cr(VI) was achieved using diluted base solutions that may allow the reuse of PAN-NH2 nanofibers.

  • 281.
    Axelsson, Mathias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Transparent conductive oxides deposited by magnetron sputtering: synthesis and characterization2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The thesis has dealt with transparent conducting oxide (TCO) materials, with a focus on Al:ZnO and with studies on Sn:In2O3 and ZnO. TCOs are a material group that is used for its properties of being conductive and at the same time transparent. In solar cells, a top layer of TCO is often used to allow light to transmit into the cell and then conduct the resulting current.

     

    A set of growth parameters was chosen and optimized through a literature study and experiments. The depositied thin films were characterized by optical and electrical characterization methods. Rf-magnetron-sputtering was used as the deposition method, where the influence of O2, argon and substrate temperature were the parameters to be studied. As a part of the characterization a model for spectroscopic ellipsometry on Al:ZnO was made, enabling faster measurement of transport properties. The main parameter affecting the TCO properties was found to be oxygen flow and the optimum flow value for each material has been determined. Substrate heating did not show any significant improvement on the resistivity of Al:ZnO with a minimum value of ~5.0*10-4 Ωcm while no heating resulted in a value of ~6.0*10-4  Ωcm. These values are comparable to the state-of-the-art from the literature.

     

    As a demonstration of application, the developed AZO and ZnO were applied to CIGS solar cells and these were compared to a reference. The newly developed AZO and ZnO was comparable to the reference but a lower mean fill factor indicates that improvements can be made.

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  • 282.
    Ayatollahi, Azadeh
    et al.
    Ferdowsi Univ Mashhad, Fac Sci, Dept Phys, Mashhad, Razavi Khorasan, Iran..
    Roknabadi, Mahmood Rezaee
    Ferdowsi Univ Mashhad, Fac Sci, Dept Phys, Mashhad, Razavi Khorasan, Iran..
    Behdani, Mohammad
    Ferdowsi Univ Mashhad, Fac Sci, Dept Phys, Mashhad, Razavi Khorasan, Iran..
    Shahtahmassebi, Nasser
    Ferdowsi Univ Mashhad, Fac Sci, Dept Phys, Mashhad, Razavi Khorasan, Iran..
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Adsorption characteristics of amino acids on graphene and germanene using dispersion-corrected density functional theory2021In: Physica. E, Low-Dimensional systems and nanostructures, ISSN 1386-9477, E-ISSN 1873-1759, Vol. 127, article id 114498Article in journal (Refereed)
    Abstract [en]

    In the present study, we have explored the interaction of five distinct kinds of amino acid molecules namely, arginine (Arg), aspartic acid (Asp), alanine (Ala), asparagine (Asn) and histidine (His) with graphene and germanene monolayers employing dispersion-corrected density functional theory. The dispersion correction incorporated in the computational methodology improves the accuracy of the results by taking into account the long range van der Waals interactions between the adsorbent and adsorbate. Using this method, the equilibrium configuration, energetic, electronic and optical properties of amino acids adsorbed on substrate have systematically been found. It is also found that arginine makes the most stable complexes with graphene and germanene in comparison to the other amino acids used in this study. Compared to graphene, germanene shows higher sensitivity to amino acids indicating that germanene monolayers can be useful for bio-integrated electronic devices.

  • 283. Aydin, M.
    et al.
    Unal, B.
    Esat, B.
    Baykal, A.
    Karaoglu, E.
    Toprak, Muhammet Sadaka
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Sozeri, H.
    Synthesis, magnetic and electrical characteristics of poly(2-thiophen-3-yl-malonic acid)/Fe(3)O(4) nanocomposite2012In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 514, p. 45-53Article in journal (Refereed)
    Abstract [en]

    Poly(2-thiophen-3-yl-malonic acid)/Fe(3)O(4) nanocomposite was synthesized by the precipitation of Fe(3)O(4) in the presence of poly(2-thiophen-3-yl-malonic acid) (PT3MA). Characterizations of the nanocomposite were performed by XRD, FT-IR, TEM, TGA, AC/DC conductivity and dielectric measurements. The capping of PT3MA around Fe(3)O(4) nanoparticles was confirmed by FTIR spectroscopy, the interaction being between bridging oxygen of the carboxylate and the nanoparticle surface through bidentate binding. The crystallite particle sizes of 6 +/- 3 nm and 7 +/- 3 nm were obtained from XRD line profile fitting and from TEM image analysis respectively, and they are in good agreement with each other. Magnetization measurements revealed that PT3MA coated magnetite particles do not saturate at higher fields. The material showed superparamagnetic character as revealed by the absence of coercivity and remnant magnetization. Magnetic particle size was calculated as 7.3 +/- 1.0 nm from the mean magnetization term in the Langevin function which is also in conformity with the values determined from TEM micrographs and XRD line profile fitting. The TEM particle size analysis of the nanoparticles revealed the presence of a slightly modified magnetically dead nanoparticle surface. AC and DC conductivity measurements were performed to elucidate the electrical conduction characteristics of the product.

  • 284. Ayedh, H. M.
    et al.
    Bathen, M. E.
    Galeckas, A.
    Hassan, J. U.
    Bergman, J. P.
    Nipoti, R.
    Hallén, Anders
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Integrated devices and circuits.
    Svensson, B. G.
    Controlling the carbon vacancy in 4H-SiC by thermal processing2018In: ECS Transactions, Electrochemical Society Inc. , 2018, no 12, p. 91-97Conference paper (Refereed)
    Abstract [en]

    The carbon vacancy (Vc) is perhaps the most prominent point defect in silicon carbide (SiC) and it is an efficient charge carrier lifetime killer in high-purity epitaxial layers of 4H-SÌC. The Vc concentration needs to be controlled and minimized for optimum materials and device performance, and an approach based on post-growth thermal processing under C-rich ambient conditions is presented. It utilizes thermodynamic equilibration and after heat treatment at 1500 °C for 1 h, the Vc concentration is shown to be reduced by a factor-25 relative to that in as-grown state-of-the-art epi-layers. Concurrently, a considerable enhancement of the carrier lifetime occurs throughout the whole of >40 urn thick epi-layers. 

  • 285.
    Ayedh, Hussein M.
    et al.
    University of Oslo, Department of Physics, Center for Materials Science and Nanotechnology, N-0316 Oslo, NORWAY .
    Baathen, Marianne E.
    University of Oslo, Department of Physics, Center for Materials Science and Nanotechnology, N-0316 Oslo, NORWAY .
    Galeckas, Augustinas
    University of Oslo, Department of Physics, Center for Materials Science and Nanotechnology, N-0316 Oslo, NORWAY .
    ul-Hassan, Jawad
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Bergman, Peder
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Nipoti, Roberta
    CNR-IMM of Bologna, I-40129 Bologna, ITALY.
    Hallen, Anders
    Royal Institute of Technology, KTH, School of Information and Communication Technology, SE-164 40 Kista-Stockholm, SWEDEN.
    Svensson, Bengt G
    University of Oslo, Department of Physics, Center for Materials Science and Nanotechnology, N-0316 Oslo, NORWAY.
    (Invited) Controlling the Carbon Vacancy in 4H-SiC by Thermal Processing2018In: / [ed] Dudley, M; Bakowski, M; Shenai, K; Ohtani, N; Raghothamachar, B, Electrochemical Society, 2018, Vol. 86, no 12, p. 91-97Conference paper (Refereed)
    Abstract [en]

    The carbon vacancy (VC) is perhaps the most prominent point defect in silicon carbide (SiC) and it is an efficient charge carrier lifetime killer in high-purity epitaxial layers of 4H-SiC. The VC concentration needs to be controlled and minimized for optimum materials and device performance, and an approach based on post-growth thermal processing under C-rich ambient conditions is presented. It utilizes thermodynamic equilibration and after heat treatment at 1500 °C for 1 h, the VC concentration is shown to be reduced by a factor ~25 relative to that in as-grown state-of-the-art epi-layers. Concurrently, a considerable enhancement of the carrier lifetime occurs throughout the whole of >40 µm thick epi-layers.

  • 286.
    Ayyer, Kartik
    et al.
    Max Planck Inst Struct & Dynam Matter, D-22761 Hamburg, Germany.;Ctr Free Electron Laser Sci, D-22761 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany..
    Xavier, P. Lourdu
    Max Planck Inst Struct & Dynam Matter, D-22761 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany..
    Bielecki, Johan
    European XFEL, D-22869 Schenefeld, Germany..
    Shen, Zhou
    Natl Univ Singapore, Ctr Biolmaging Sci, Singapore 117557, Singapore..
    Daurer, Benedikt J.
    Natl Univ Singapore, Ctr Biolmaging Sci, Singapore 117557, Singapore..
    Samanta, Amit K.
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany..
    Awel, Salah
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany..
    Bean, Richard
    European XFEL, D-22869 Schenefeld, Germany..
    Barty, Anton
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany..
    Bergemann, Martin
    European XFEL, D-22869 Schenefeld, Germany..
    Ekeberg, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Estillore, Armando D.
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany..
    Fangohr, Hans
    European XFEL, D-22869 Schenefeld, Germany..
    Giewekemeyer, Klaus
    European XFEL, D-22869 Schenefeld, Germany..
    Hunter, Mark S.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Karnevskiy, Mikhail
    European XFEL, D-22869 Schenefeld, Germany..
    Kirian, Richard A.
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA..
    Kirkwood, Henry
    European XFEL, D-22869 Schenefeld, Germany..
    Kim, Yoonhee
    European XFEL, D-22869 Schenefeld, Germany..
    Koliyadu, Jayanath
    European XFEL, D-22869 Schenefeld, Germany..
    Lange, Holger
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Univ Hamburg, Inst Phys Chem, D-20146 Hamburg, Germany..
    Letrun, Romain
    European XFEL, D-22869 Schenefeld, Germany..
    Lübke, Jannik
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, D-22761 Hamburg, Germany..
    Michelat, Thomas
    European XFEL, D-22869 Schenefeld, Germany..
    Morgan, Andrew J.
    Univ Melbourne, Phys, Melbourne, Vic, Australia..
    Roth, Nils
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, D-22761 Hamburg, Germany..
    Sato, Tokushi
    European XFEL, D-22869 Schenefeld, Germany..
    Sikorski, Margin
    European XFEL, D-22869 Schenefeld, Germany..
    Schulz, Florian
    Univ Hamburg, Inst Phys Chem, D-20146 Hamburg, Germany..
    Spence, John C. H.
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA..
    Vagovic, Patrik
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;European XFEL, D-22869 Schenefeld, Germany..
    Wollweber, Tamme
    Max Planck Inst Struct & Dynam Matter, D-22761 Hamburg, Germany.;Ctr Free Electron Laser Sci, D-22761 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany..
    Worbs, Lena
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, D-22761 Hamburg, Germany..
    Yefanov, Oleksandr
    Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany..
    Zhuang, Yulong
    Max Planck Inst Struct & Dynam Matter, D-22761 Hamburg, Germany.;Ctr Free Electron Laser Sci, D-22761 Hamburg, Germany..
    Maia, Filipe R.N.C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics. NERSC, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Horke, Daniel A.
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;Radboud Univ Nijmegen, Inst Mol & Mat, NL-6525 AJ Nijmegen, Netherlands..
    Küpper, Jochen
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, D-22761 Hamburg, Germany.;Univ Hamburg, Dept Chem, D-20146 Hamburg, Germany..
    Loh, N. Duane
    Natl Univ Singapore, Ctr Biolmaging Sci, Singapore 117557, Singapore.;Natl Univ Singapore, Dept Phys, Singapore 117551, Singapore..
    Mancuso, Adrian P.
    European XFEL, D-22869 Schenefeld, Germany.;La Trobe Univ, La Trobe Inst Mol Sci, Dept Chem & Phys, Melbourne, Vic 3086, Australia..
    Chapman, Henry N.
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Ctr Free Electron LaserSci, DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, D-22761 Hamburg, Germany..
    3D diffractive imaging of nanoparticle ensembles using an x-ray laser2021In: Optica, E-ISSN 2334-2536, Vol. 8, no 1, p. 15-23Article in journal (Refereed)
    Abstract [en]

    Single particle imaging at x-ray free electron lasers (XFELs) has the potential to determine the structure and dynamics of single biomolecules at room temperature. Two major hurdles have prevented this potential from being reached, namely, the collection of sufficient high-quality diffraction patterns and robust computational purification to overcome structural heterogeneity. We report the breaking of both of these barriers using gold nanoparticle test samples, recording around 10 million diffraction patterns at the European XFEL and structurally and orientationally sorting the patterns to obtain better than 3-nm-resolution 3D reconstructions for each of four samples. With these new developments, integrating advancements in x-ray sources, fast-framing detectors, efficient sample delivery, and data analysis algorithms, we illuminate the path towards sub-nano meter biomolecular imaging. The methods developed here can also be extended to characterize ensembles that are inherently diverse to obtain their full structural landscape. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.

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  • 287.
    Azadpour, Behnam
    et al.
    Univ Tehran, Coll Engn, Adv Magnet Mat Res Ctr, Sch Met & Mat, Tehran 111554563, Iran.;Univ Tehran, Coll Sci, Sch Biol, Tehran 111554563, Iran..
    Kashanian, Faezeh
    Univ Tehran, Coll Sci, Sch Biol, Tehran 111554563, Iran..
    Habibi-Rezaei, Mehran
    Univ Tehran, Coll Sci, Sch Biol, Tehran 111554563, Iran..
    Ebrahimi, Seyyed Ali Seyyed
    Univ Tehran, Coll Engn, Adv Magnet Mat Res Ctr, Sch Met & Mat, Tehran 111554563, Iran..
    Yazdanpanah, Roozbeh
    Univ Tehran, Coll Engn, Adv Magnet Mat Res Ctr, Sch Met & Mat, Tehran 111554563, Iran.;Univ Tehran, Coll Sci, Sch Biol, Tehran 111554563, Iran..
    Lalegani, Zahra
    Univ Tehran, Coll Engn, Adv Magnet Mat Res Ctr, Sch Met & Mat, Tehran 111554563, Iran..
    Hamawandi, Bejan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Covalently-Bonded Coating of L-Arginine Modified Magnetic Nanoparticles with Dextran Using Co-Precipitation Method2022In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 15, no 24, article id 8762Article in journal (Refereed)
    Abstract [en]

    In this study, L-arginine (Arg) modified magnetite (Fe3O4) nanoparticles (RMNPs) were firstly synthesized through a one-step co-precipitation method, and then these aminated nanoparticles (NPs) were, again, coated by pre-oxidized dextran (Dext), in which aldehyde groups (DextCHO) have been introduced on the polymer chain successfully via a strong chemical linkage. Arg, an amino acid, acts as a mediator to link the Dext to a magnetic core. The as-synthesized Arg-modified and Dext-coated arginine modified Fe3O4 NPs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Both synthesized samples, XRD pattern and FT-IR spectra proved that the core is magnetite. FT-IR confirmed that the chemical bonds of Arg and Dext both exist in the samples. SEM images showed that the NPs are spherical and have an acceptable distribution size, and the VSM analysis indicated the superparamagnetic behavior of samples. The saturation magnetization was decreased after Dext coating, which confirms successive coating RMNPs with Text. In addition, the TGA analysis demonstrated that the prepared magnetic nanocomposites underwent various weight loss levels, which admitted the modification of magnetic cores with Arg and further coating with Dext.

  • 288.
    Azina, Clio
    et al.
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Bartsch, Tim
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Holzapfel, Damian M.
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Dahlqvist, Martin
    Linköping Univ, Dept Phys Chem & Biol IFM, Mat Design, Linköping, Sweden..
    Rosen, Johanna
    Linköping Univ, Dept Phys Chem & Biol IFM, Mat Design, Linköping, Sweden..
    Lofler, Lukas
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Mendez, Alba San Jose
    Deutsch Elektronen Synchrotron DESY, Hamburg, Germany..
    Hans, Marcus
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Schneider, Jochen M.
    Rhein Westfal TH Aachen, Mat Chem, Kopernikusstr 10, D-52074 Aachen, Germany..
    Yttrium incorporation in Cr2AlC: On the metastable phase formation and decomposition of (Cr,Y)(2)AlC MAX phase thin films2023In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 106, no 4, p. 2652-2665Article in journal (Refereed)
    Abstract [en]

    Herein we report on the synthesis of a metastable (Cr,Y)(2)AlC MAX phase solid solution by co-sputtering from a composite Cr-Al-C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760 degrees C led to the formation of phase pure (Cr,Y)(2)AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr2AlC, Y5Al3, and Cr-carbides. In contrast to pure Cr2AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by similar to 200 degrees C for 5 at.% Y compared to Cr2AlC. Calculations predicting the metastable phase formation of (Cr,Y)(2)AlC and its decomposition are in excellent agreement with the experimental findings.

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  • 289.
    Azina, Clio
    et al.
    Rhein Westfal TH Aachen, Germany.
    Bartsch, Tim
    Rhein Westfal TH Aachen, Germany.
    Holzapfel, Damian M.
    Rhein Westfal TH Aachen, Germany.
    Dahlqvist, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Materials design. Linköping University, Faculty of Science & Engineering.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Materials design. Linköping University, Faculty of Science & Engineering.
    Lofler, Lukas
    Rhein Westfal TH Aachen, Germany.
    Mendez, Alba San Jose
    Deutsch Elektronen Synchrotron DESY, Germany.
    Hans, Marcus
    Rhein Westfal TH Aachen, Germany.
    Primetzhofer, Daniel
    Uppsala Univ, Sweden.
    Schneider, Jochen M.
    Rhein Westfal TH Aachen, Germany.
    Yttrium incorporation in Cr2AlC: On the metastable phase formation and decomposition of (Cr,Y)(2)AlC MAX phase thin films2023In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 106, no 4, p. 2652-2665Article in journal (Refereed)
    Abstract [en]

    Herein we report on the synthesis of a metastable (Cr,Y)(2)AlC MAX phase solid solution by co-sputtering from a composite Cr-Al-C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760 degrees C led to the formation of phase pure (Cr,Y)(2)AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr2AlC, Y5Al3, and Cr-carbides. In contrast to pure Cr2AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by similar to 200 degrees C for 5 at.% Y compared to Cr2AlC. Calculations predicting the metastable phase formation of (Cr,Y)(2)AlC and its decomposition are in excellent agreement with the experimental findings.

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  • 290.
    Azina, Clio
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Rhein Westfal TH Aachen, Germany.
    Mraz, Stanislav
    Rhein Westfal TH Aachen, Germany.
    Greczynski, Grzegorz
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hans, Marcus
    Rhein Westfal TH Aachen, Germany.
    Primetzhofer, Daniel
    Uppsala Univ, Sweden.
    Schneider, Jochen M.
    Rhein Westfal TH Aachen, Germany.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Oxidation behaviour of V2AlC MAX phase coatings2020In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 40, no 13, p. 4436-4444Article in journal (Refereed)
    Abstract [en]

    We report on the oxidation behaviour of V2AlC coatings up to 800 degrees C, in air. The coatings were deposited at 580 degrees C using magnetron sputtering from a powder metallurgical composite V2AlC target and were subsequently oxidised for 5, 15 and 30 min. The microstructural evolution of the samples was investigated, and X-ray diffraction patterns were collected to track the formation of oxides. The first indications of oxidation appear after just 15 min at 500 degrees C, as V-based oxides grew on the surface of the coatings. Later, the presence of mostly V-based oxides and ternary (V, Al)-oxides was observed starting after 5 min at 600 degrees C. Further analyses confirmed outward diffusion of V and inward diffusion of O, while Al tends to sublimate. alpha-A12O3 was only indexed after 5 min at 800 degrees C. Ex-situ electrical resistivity measurements allowed tracking the oxidation progress of the V2AlC coating.

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  • 291.
    Azina, Clio
    et al.
    Linkoping Univ, Dept Phys Chem & Biol IFM, Thin Film Phys Div, SE-58183 Linkoping, Sweden.;Rhein Westfal TH Aachen, Mat Chem, Kope 10, D-52074 Aachen, Germany..
    Mraz, Stanislav
    Rhein Westfal TH Aachen, Mat Chem, Kope 10, D-52074 Aachen, Germany..
    Greczynski, Grzegorz
    Linkoping Univ, Dept Phys Chem & Biol IFM, Thin Film Phys Div, SE-58183 Linkoping, Sweden..
    Hans, Marcus
    Rhein Westfal TH Aachen, Mat Chem, Kope 10, D-52074 Aachen, Germany..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Schneider, Jochen M.
    Rhein Westfal TH Aachen, Mat Chem, Kope 10, D-52074 Aachen, Germany..
    Eklund, Per
    Linkoping Univ, Dept Phys Chem & Biol IFM, Thin Film Phys Div, SE-58183 Linkoping, Sweden..
    Oxidation behaviour of V2AlC MAX phase coatings2020In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 40, no 13, p. 4436-4444Article in journal (Refereed)
    Abstract [en]

    We report on the oxidation behaviour of V2AlC coatings up to 800 degrees C, in air. The coatings were deposited at 580 degrees C using magnetron sputtering from a powder metallurgical composite V2AlC target and were subsequently oxidised for 5, 15 and 30 min. The microstructural evolution of the samples was investigated, and X-ray diffraction patterns were collected to track the formation of oxides. The first indications of oxidation appear after just 15 min at 500 degrees C, as V-based oxides grew on the surface of the coatings. Later, the presence of mostly V-based oxides and ternary (V, Al)-oxides was observed starting after 5 min at 600 degrees C. Further analyses confirmed outward diffusion of V and inward diffusion of O, while Al tends to sublimate. alpha-A12O3 was only indexed after 5 min at 800 degrees C. Ex-situ electrical resistivity measurements allowed tracking the oxidation progress of the V2AlC coating.

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  • 292.
    Aziz, Baroz
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Synthesis and modification of potential CO2 adsorbents: Amine modified silica and calcium carbonates2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The prospect of rapid changes to the climate due to global warming is subject of public concern. The need to reduce the emissions of atmospheric green house gases and in particular carbon dioxide is greater than ever. Extensive research is performed to find new solutions and new materials, which tackles this problem in economically benign way. This thesis dealt with two potential adsorbents for post combustion  carbon capture, namely, amine modified silica and calcium carbonates. We modified porous silica with large surface area by propyl-amine groups to enhance the carbon dioxide adsorption capacity and selectivity. Experimental parameters, such as reaction time, temperature, water content, acid and heat treatment of silica substrate were optimized using a fractional factorial design. Adsorption properties and the nature of formed species upon reaction of CO2 and amine-modified silica were studied by sorption and infrared spectroscopy. Physisorbed and chemisorbed amount of adsorbed CO2 were, for the first time, estimated directly in an accurate way. The effects of temperature and moisture on the CO2 adsorption properties were also studied.

    Crystallization of calcium carbonate as a precursor to calcium oxide, which can be used as carbon dioxide absorbent, was studied in the second part of this thesis. Structure of different amorphous phases of calcium carbonate was studied in detail. Crystallization of calcium carbonate with and without additives was studied. Parameters like stirring rate, temperature, pH and polymer concentration showed to be important in selection of phase and morphology. An aggregation mediated crystallization was postulated to explain the observed morphologies. 

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  • 293.
    Aziz, Baroz
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Gebauer, Denis
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kinetic control of particle-mediated calcium carbonate crystallization2011In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 13, no 14, p. 4641-4645Article in journal (Refereed)
    Abstract [en]

    By changing the temperature, pH, stirring rate, or time for calcium carbonate crystallization, complex shapes of aggregated calcium carbonates formed. Such shapes have earlier been ascribed to specific interactions with specialized additives. Without polymeric additives, aggregates of vaterite transformed more rapidly into calcite aggregates under slow than under fast stirring. With an anionic polyelectrolyte added, vaterite was stabilized. Larger polycrystalline aggregates of vaterite formed under rapid than under slow stirring, indicative of a particle mediated growth of aggregates controlled by convective currents. The size of the underlying nanoparticles was temperature dependent, with grain sizes of similar to 20 to 50 nm at 20 degrees C and similar to 350 nm at 90 degrees C. The small differences in free energy between the anhydrous polymorphs of calcium carbonate made both kinetic and equilibrium dependencies important.

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  • 294.
    Aziz, Baroz
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Materials Chemistry.
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Materials Chemistry.
    Bacsik, Zoltán
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Materials Chemistry.
    Quantification of chemisorption and physisorption of carbon dioxide on porous silica modified by propylamines: Effect of amine density2012In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 159, p. 42-49Article in journal (Refereed)
    Abstract [en]

    Detailed molecular aspects of carbon dioxide sorption on porous silica with different amounts of tethered and cross-linked n-propylamine groups were investigated. Infrared spectroscopy was applied to directly quantify physisorbed and chemisorbed CO2 on the amine modified silicas. The fractions of physisorbed CO2 and various chemisorbed species were determined as functions of CO2 pressure and the amine density on the modified silica. Physisorbed CO2 was a minor portion of the total CO2 uptake at low pressures, but it’s contribution increased to ∼35% at 1 bar of CO2 when the propylamine surface density was low or medium (0.87-1.67 NH2/nm2). Chemisorption of CO2 dominated when the propylamine content was high (2.74 NH2/nm2). The quantities of propylammonium propylcarbamate ion pairs increased with increasing propylamine content. At low or medium amine surface densities (0.87-1.67 NH2/nm2) this increase was approximately proportional to the amine density, but the quantity of ion pairs increased very significantly when the propylamine content was high (2.74 NH2/nm2). This dependency on amine density is consistent with the idea that a sufficiently close proximity of propylamine groups allows a formation of ion pairs. The relative fractions of carbamic acid and silylpropylcarbamate were significant for materials on which ion pairs could not form. Furthermore, the quantities of carbamic acid increased with increasing amine densities suggesting that the ion pairs have a role to stabilize the labile carbamic acid through hydrogen bonds.

  • 295.
    Aziz, Baroz
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zhao, Guoying
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Carbon Dioxide Sorbents with Propylamine Groups-Silica Functionalized with a Fractional Factorial Design Approach2011In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 27, no 7, p. 3822-3834Article in journal (Refereed)
    Abstract [en]

    Mesoporous silica particles (Davisil) were functionalized with aminopropyltriethoxysilane (APTES) in a fractional factorial design with 19 different synthesis and uptake experiments. The number of amino groups and the uptake of CO(2) were optimized in a 2(V)(5-1) design. Most important to functionalizationwas the amount of water present during synthesis, the reaction time, and pretreating the silica with a mineral acid; certain two-way interactions were shown to be statistically significant as well. Modifications performed at 110 or 80 degrees C showed no significant differences concerning amine content or uptake of CO(2). Properly choosing center points for the discrete variables is problematic and is somewhat related to the lack of fit with respect to CO(2) uptake; the regression was good. Solid-state (29)Si NMR showed that the APTES was mainly fully condensed. Specific surface areas did not correlate with the number of n-propylamine groups on the silica, which is indicative of differential levels of heterogeneity in the coverage of propylamines. The uptake of CO(2) and N(2) was measured from -20 to 70 degrees C and from 0 to 1 bar and parametrized by the Freundlich isotherm. Amine-modified silica adsorbed significant amounts of CO(2), especially at the low partial pressure, which is important for CO(2) capture from flue gas. At such pressures, samples with a high density of amine (4 amines/nm(2)) showed a much higher uptake of CO(2) than did those with densities of similar to 2-3 amines/nm(2), reflecting differential tendencies to form propylammonium-propylcarbamate ion pairs; these require close proximity among amine groups to form. Water affected the uptake of carbon dioxide in different ways. Certain samples took up more moist CO(2) gas than dry CO(2), and others took up less moist CO(2) than dry CO(2), which is indicative of differential tendencies toward water adsorption. We conclude that experimental design is a time-efficient approach to the functionalization of silica with propylamine groups.

  • 296.
    Aziz, Shazed
    et al.
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia.
    Rashid, Suraya
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia; Advanced Materials and Nanotechnology Lab , Institute of Advanced Technology, University Putra Malaysia, Selangor, Malaysia.
    Salleh, Mohamad Amran Mohd
    Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia; Advanced Materials and Nanotechnology Lab, Institute of Advanced Technology, University Putra Malaysia, Selangor, Malaysia.
    Theoretical Prediction of CNT-CF/PP Composite Tensile Properties Using Various Numerical Modeling Methods2013In: Fullerenes, nanotubes, and carbon nanostructures, ISSN 1536-383X, E-ISSN 1536-4046, Vol. 21, no 5, p. 411-416Article in journal (Refereed)
    Abstract [en]

    Development of effective models to predict tensile properties of ‘carbon nanotube coated carbon fibre reinforced polypropylene (CNT-CF/PP)’ composites is briefly discussed. The composite taken as the reference is based on the highest growth mechanism of CNTs over carbon fibres. Halpin-Tsai and Combined Voigt-Reuss model has been implemented. Young's modulus for CNT-CF/PP composites has been found 4.5368 GPa and the tensile strength has been estimated 45.367 MPa considering the optimum operating condition of chemical vapor deposition (CVD) technique. Stiffness of the composite is represented through the stress-strain plots; stiffness is proportional to the steepness of the slope. There are slight deviations of results that have been found theoretically over the experimental issues.

  • 297.
    B. Brant Carvalho, Paulo H.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Pressure-Induced Amorphization and Distinct Amorphous States of Clathrate Hydrates2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis summarizes a study on the pressure-induced amorphization (PIA) and structures of amorphous states of clathrate hydrates (CHs).

    PIA involves the transition of a crystalline material into an amorphous solid in response of mechanical compression at temperatures well below the melting point. The first material observed to undergo PIA was hexagonal ice. More recently it was shown that compounds of water undergo the same phenomenon without decomposition, despite the presence of solutes. CHs, which are crystalline inclusion compounds consisting of water molecules encaging small guest species, undergo PIA at ca. 1–4 GPa below 145 K. The obtained amorphous CH phase can be further densified on isobaric heating at high pressure. This annealing step enables to retain an amorphous material on pressure release. There has been a significant amount of studies into the understanding of the nature of PIA and transformations between amorphous phases of pure ice. The aim of this thesis has been the understanding of the PIA in CHs and its relation to pure ice. New information on the nature of PIA and subsequent amorphous-amorphous transitions in CH systems were gained from structural studies and in situ neutron diffraction played pivotal role due to the sensitivity of neutrons to the light element hydrogen. Here a generalized understanding of the PIA in CHs and a clear image of amorphous CH structures are presented.

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  • 298.
    Baba, Elbruz Murat
    et al.
    Inst Energy Technol, Dept Solar Energy, NO-2027 Kjeller, Norway.;Istanbul Tech Univ, Nanosci & Nano Engn Dept, TR-34469 Istanbul, Turkey..
    Montero, José Amenedo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Moldarev, Dmitrii
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. Inst En MEPhI, Dept Mat Sci, Kashirskoe Shosse 31, Moscow 115409, Russia..
    Moro, Marcos V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Wolff, Max
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. Natl Res Nucl Univ MEPhI, Dept Mat Sci, Kashirskoe Shosse 31, Moscow 115409, Russia..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Sartori, Sabrina
    Univ Oslo, Dept Technol Syst, NO-2027 Kjeller, Norway..
    Zayim, Esra
    Istanbul Tech Univ, Nanosci & Nano Engn Dept, TR-34469 Istanbul, Turkey.;Istanbul Tech Univ, Fac Sci & Letters, Phys Engn Dept, TR-34469 Istanbul, Turkey..
    Karazhanov, Smagul
    Inst Energy Technol, Dept Solar Energy, NO-2027 Kjeller, Norway.;Natl Res Nucl Univ MEPhI, Dept Mat Sci, Kashirskoe Shosse 31, Moscow 115409, Russia..
    Preferential Orientation of Photochromic Gadolinium Oxyhydride Films2020In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 25, no 14, article id 3181Article in journal (Refereed)
    Abstract [en]

    We report preferential orientation control in photochromic gadolinium oxyhydride (GdHO) thin films deposited by a two-step process. Gadolinium hydride (GdH2-x) films were grown by reactive magnetron sputtering, followed by oxidation in air. The preferential orientation, grain size, anion concentrations and photochromic response of the films were strongly dependent on the deposition pressure. The GdHO films showed a preferential orientation along the [100] direction and exhibited photochromism when synthesized at deposition pressures of up to 5.8 Pa. The photochromic contrast was larger than 20% when the films were deposited below 2.8 Pa with a 0.22 H-2/Ar flow ratio. We argue that the relation of preferential orientation and the post deposition oxidation since oxygen concentration is known to be a key parameter for photochromism in rare-earth oxyhydride thin films. The experimental observations described above were explained by the decrease of the grain size as a result of the increase of the deposition pressure of the sputtering gas, followed by a higher oxygen incorporation.

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  • 299.
    Babanejad, Safoura
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ahmed, Hesham
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. Central Metallurgical Research and Development Institute, P.O. Box 87, Helwan 114 21, Egypt.
    Andersson, Charlotte
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Samuelsson, Caisa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Lennartsson, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Hall, Björn
    Stena Recycling International AB, P.O. Box 4088, 400 40 Gothenburg, Sweden.
    Arnerlöf, Linn
    Boliden Smelters, Klarabergsviadukten 90 A, Stockholm, Sweden.
    High-Temperature Behavior of Spent Li-Ion Battery Black Mass in Inert Atmosphere2022In: Journal of Sustainable Metallurgy, ISSN 2199-3823, Vol. 8, p. 566-581Article in journal (Refereed)
    Abstract [en]

    The increased demand for Li-ion batteries has prompted the scientific community to improve recycling routes in order to reuse the valuable materials in batteries. After their end-of-life, the batteries are collected, discharged, and mechanically disintegrated, generating plastic and metallic streams that are recycled directly; this leaves behind a small particle size fraction known as black mass (BM). BM is composed mainly of graphite and Li-metal complex oxides. Pyrometallurgy is a route known for recycling of BM, in which identifying the BM’s behavior at high temperatures is essential. In this study, two types of BM are characterized in two fractions of 150–700 µm and smaller than 150 µm. The thermal behavior of the BM is studied with thermal analysis techniques. The analyses demonstrate that the mineralogical and morphological properties of the two fractions do not significantly differ, while the amounts of C and organic materials might vary. When the BM was thermally treated, the binders decomposed until a temperature of 500 ℃ was reached, where the volatilization of hydrocarbons was observed, although F mostly persisted in the BM. The Li-metal oxide was partially reduced to lower oxides and Li carbonate at ⁓ 600 ℃, and the main mass loss was caused by carbothermic reduction immediately thereafter. As the products of this process, metallic Co and Ni phases were formed, and part of the graphite remained unreacted. Regarding the Li behavior, it was observed that in the presence of Al, AlLiO2 is the most likely composition to form, and it changes to LiF by increasing the F concentration in the composition.

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  • 300. Babonas, G. J.
    et al.
    Reza, A.
    Simkiene, I.
    Sabataityte, J.
    Baran, M.
    Szymczak, R.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Suchodolski, Arturas
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Optical properties of Fe-doped silica films on Si2006In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 252, no 15, p. 5391-5394Article in journal (Refereed)
    Abstract [en]

    Optical properties of Fe-doped silica films on Si were investigated by ellipsometric technique in the region 1-5 eV. Samples were produced by sol-gel method. Precursors were prepared by mixing tetraethoxysilane (TEOS) solution in ethanol and water with aqueous solution of Fe-chloride or Fe-acetate. The coating solution was deposited on Si substrates by spin on technique. The size of Fe-containing nanometric-sized particles depended on technology and varied from 20 to 100 nm. Optical response of complex hybrid samples SiO2:Fe/Si was interpreted in a multi-layer model. In the inverse problem, the Maxwell equations were solved by transfer matrix technique. Dielectric function of Fe-doped silica layers was calculated in the model of effective media. Analysis of optical data has shown that various Fe-oxides formed. Experimental data for films obtained from precursors with Fe-acetate and annealed in hydrogen were well described by the model calculations taking into account a small contribution 1-5% of metal Fe imbedded in silica. The Fe/Fe-O contribution to optical response increased for samples grown from FeCl3-precursor. Ellipsometric data for Fe-doped silica films on Si were interpreted taking into account the structural AFM studies as well as the results of magnetic measurements.

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