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  • 151.
    Kolahdouz, Mohammadreza
    et al.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Hållstedt, Julius
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Wise, R.
    Radamson, Henry H.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Selective Epitaxial Growth with Full Control of Pattern Dependency Behavior for pMOSFET Structures2009In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 156, no 3, p. H169-H171Article in journal (Refereed)
    Abstract [en]

    This study presents a way to design chips to obtain uniform selective epitaxial growth of SiGe layers in p-type metal-oxide-semiconductor field-effect transistor (pMOSFET) structures. The pattern dependency behavior of the growth has been controlled over different sizes of transistors. It is shown that the exposed Si coverage of the chip is the main parameter in order to maintain control of the layer profile. This has been explained by the gas depletion theory of the growth species in the stationary boundary layer over the water. Control of the SiGe layer profile has been obtained over a wide range of device sizes by optimized process parameters in combination with a wafer pattern design consisting of dummy features causing uniform gas depletion over the chips of the wafer.

  • 152.
    Kolahdouz, Mohammadreza
    et al.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Maresca, Luca
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Ghandi, Reza
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Khatibi, Ali
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Radamson, Henry H.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Kinetic Model of SiGe Selective Epitaxial Growth Using RPCVD Technique2011In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 158, no 4, p. H457-H464Article in journal (Refereed)
    Abstract [en]

    Recently, selective epitaxial growth (SEG) of B-doped SiGe layers has been used in recessed source/drain (S/D) of pMOSFETs. The uniaxial induced strain enhances the carrier mobility in the channel. In this work, a detailed model for SEG of SiGe has been developed to predict the growth rate and Ge content of layers in dichlorosilane(DCS)-based epitaxy using a reduced-pressure CVD reactor. The model considers each gas precursor contributions from the gas-phase and the surface. The gas flow and temperature distribution were simulated in the CVD reactor and the results were exerted as input parameters for Maxwell energy distribution. The diffusion of molecules from the gas boundaries was calculated by Fick's law and Langmuir isotherm theory (in non-equilibrium case) was applied to analyze the surface. The pattern dependency of the selective growth was also modeled through an interaction theory between different subdivisions of the chips. Overall, a good agreement between the kinetic model and the experimental data were obtained.

  • 153.
    Kolahdouz, Mohammadreza
    et al.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Salemi, Arash
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Moeen, Mahdi
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Radamson, Henry H.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Kinetic Modeling of Low Temperature Epitaxy Growth of SiGe Using Disilane and Digermane2012In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 159, no 5, p. H478-H481Article in journal (Refereed)
    Abstract [en]

    Low temperature epitaxy (LTE) in Chemical Vapor Deposition (CVD) refers to 350-650 degrees C interval. This temperature range is critical for this process since the thermal and lattice mismatch (or strain relaxation) issues diminish in advanced BiCMOS processing. The modeling of the epitaxy process is a vital task to increase the understanding the growth process and to design any desired device structure. In this study, an empirical model for Si2H6/Ge2H6-based LTE of SiGe is developed and compared with experimental work. The model can predict the number of free sites on Si surface, growth rate of Si and SiGe, and the Ge content at low temperatures. A good agreement between the model and the experimental data is obtained.

  • 154.
    Kristiansen, P. T.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics. Max Planck Gesell, Fritz Haber Inst, Abt Anorgam Chem, D-14195 Berlin, Germany..
    Massel, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Werme, L.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Lilja, C.
    Swedish Nucl Fuel & Waste Management Co, SE-10124 Stockholm, Sweden..
    Duda, Laurent
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Sulfidation of Single-Phase Oxide on Copper and as Powder Studied Using Soft X-Ray Spectroscopy2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 14, p. C785-C791Article in journal (Refereed)
    Abstract [en]

    The high corrosion resistance of copper is a key feature in the design of copper-lined canisters that will be utilized to protect people and the environment from dangers of spent nuclear fuel far into the future. Our present study sheds light on the effects that sulfide ions in otherwise relatively benign anoxic groundwater may have on the copper of the container material. Using soft X-ray spectroscopy, we have studied the chemistry of the transformation of single-phase copper oxide cover layers (cuprite, tenorite, paratacamite) as well as single-phase oxide powders (paratacamite and malachite) when exposed to aqueous sulfide solutions. While X-ray diffraction shows that the main bulk of the oxides are nearly unaffected, Cu L-edge absorption spectroscopy shows that a cover layer of about 100 nm thickness on the metal substrate is transformed from Cu(II)- to Cu(I)-species. By contrast, paratacamite and malachite powders exposed to the same kind of aqueous sulfide solutions show much less transformation to Cu(I)-species. We conclude that the main mechanism for reduction of Cu(II) on copper is the comproportionation reaction between divalent copper ions from the covering oxide and the underlying metallic copper atoms to form monovalent copper ions. By contrast, the absence of metallic copper inhibits this mechanism in the powders.

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  • 155. Krogh, O
    et al.
    Slomowitz, H
    Melaku, Y
    Blom, Hans-Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Spectroscopy diagnostics of phoresist in an aluminium etch plasma1987In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 134, no 8Article in journal (Refereed)
  • 156.
    Kuhn, Joel
    et al.
    University of Toronto, Department of Mechanical and Industrial Engineering, Toronto, Ontario M5S 3G8, Canada.
    Gupta, Mohit Kumar
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Kesler, Olivera
    University of Toronto, Department of Mechanical and Industrial Engineering, Toronto, Ontario M5S 3G8, Canada.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    The Effect of Fuel Electrode Roughness on the Properties of Plasma Sprayed Solid Oxide Cells2018In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 165, no 9, p. F693-F701Article in journal (Refereed)
    Abstract [en]

    Solid oxide cell electrolytes fabricated by atmospheric plasma spraying are frequently found to have considerable gas leak rates.Electrode surface roughness is known to have an influence on electrolyte leak rates. A jet of high velocity air, produced with an airknife, was aimed at the plasma plume during fuel electrode deposition to reduce the surface roughness prior to electrolyte deposition.The resulting fuel electrode masses, electrode compositions, and electrode surface roughnesses were measured for varying air knifeinlet pressures. Surface asperity populations and maximum heights were significantly reduced using air knife pressures of >6 barat the expense of deposition efficiency. The nickel volume fraction in the fuel electrode increased slightly with increasing air knifepressure. Open circuit voltages were larger on the smoother fuel electrodes that were produced at higher air knife pressures, but nosignificant effect of air knife pressure on cell power density could be discerned.© 2018 The Electrochemical Society

  • 157.
    LAGERGREN, CARINA
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    LINDBERGH, GÖRAN
    KTH, Superseded Departments, Chemical Engineering and Technology.
    SIMONSSON, DANIEL
    KTH, Superseded Departments, Chemical Engineering and Technology.
    INVESTIGATION OF POROUS ELECTRODES BY CURRENT INTERRUPTION APPLICATION TO MOLTEN CARBONATE FUEL CELL CATHODES1995In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 142, no 3, p. 787-797Article in journal (Refereed)
    Abstract [en]

    A transient agglomerate model for simulation and analysis of experimental data, obtained by current interruption on porous molten carbonate fuel cell cathodes, is presented. The initial fast change of the potential after current interruption on a polarized NiO electrode is due to the closed-circuit potential distribution in the electrode. Conventional estimation of the iR corrected overvoltage by current interruption on porous electrodes, with finite electronic conductivity in the solid phase and a finite ionic conductivity of the pore electrolyte, leads to an overcompensation of the external potential drop and an underestimation of the total steady-state overvoltage due to the internal currents passing in the electrode after interruption. The overcompensation of the external potential drop is directly proportional to the geometric current density and to the thickness of the electrode and inversely proportional to the sum df the effective conductivities in the electrode matrix and the pore electrolyte.

  • 158.
    LAGERGREN, CARINA
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    LUNDBLAD, ANDERS
    KTH, Superseded Departments, Chemical Engineering and Technology.
    BERGMAN, BILL
    KTH, Superseded Departments, Chemical Engineering and Technology.
    SYNTHESIS AND PERFORMANCE OF LICOO2 CATHODES FOR THE MOLTEN CARBONATE FUEL CELL1994In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 141, no 11, p. 2959-2966Article in journal (Refereed)
    Abstract [en]

    A method for fabricating LiCoO2 electrodes has been developed. LiCoO2 powder was synthesized from Li2CO3 and CoCO3 powder by calcining in air at 650-degrees-C. Electrodes were tape cast in a nonaqueous slurry with and without a graphite poreformer. They were sintered in air at temperatures between 700 and 850-degrees-C. Powders and electrodes were characterized by using x-ray diffraction, thermogravimetric analysis, the Brunauer, Emmett, and Teller method, Hg porosimetry, scanning electron microscopy, and a van der Pauw conductivity measurement setup. The electrodes were electrochemically characterized by polarization measurements at different temperatures. Performance of the electrodes, with and without poreformer, respectively, was also determined by measuring polarization curves at different degrees of electrolyte fill.

  • 159.
    Lagergren, Carina
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Simonsson, Daniel
    KTH, Superseded Departments, Chemical Engineering and Technology.
    The effects of oxidant gas composition on the polarization of porous LiCoO2 electrodes for the molten carbonate fuel cell1997In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 144, no 11, p. 3813-3818Article in journal (Refereed)
    Abstract [en]

    Stationary polarization curves were obtained for porous lithium cobaltite cathodes under varying temperatures and oxidant compositions. The exchange current densities were determined from the slope at low overpotentials by means of numerical calculations, taking into account the current density distribution. Positive influences on the exchange current density were found both for the partial pressure of oxygen and carbon dioxide. The results are similar to earlier data obtained from measurements on NiO electrodes. The values are not consistent with either the peroxide mechanism or the superoxide mechanism, two mechanisms often proposed in the literature.

  • 160.
    Larsson, Fredrik
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut. Chalmers University of Technology, Sweden.
    Anderson, Johan
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Andersson, Petra
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Mellander, Bengt-Erik
    Chalmers University of Technology, Sweden.
    Thermal Modelling of Cell-to-Cell Fire Propagation and Cascading Thermal Runaway Failure Effects for Lithium-Ion Battery Cells and Modules Using Fire Walls2016In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 163, no 14, p. A2854-A2865Article in journal (Refereed)
    Abstract [en]

    A model is presented for predicting the cell-to-cell propagation of a thermal runaway/fire in a lithium-ion battery cell to neighboring cells by simulating the temperature development in neighboring cells. The modelling work comprises of two major steps; setting up a model of the cells including the thermal properties of the cells, and then validating the model through experiments where the boundary conditions in the validation test must be determined carefully. The model is developed to allow a fast evaluation of several different preventive means of thermal insulation, it is not modelling the pack and cells to a great detail. Still the experimental validation indicates that the model is good enough to fulfil its purpose of the model. A feasibility study using the model is conducted assessing two different types of fire walls between battery modules of 10 cells. The results show that there is a substantial risk for a cascading of thermal events in a battery pack, although cooling systems and fire walls may mitigate these risks

  • 161.
    Latham, Kenneth G.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Discipline of Chemistry, University of Newcastle, Callaghan, Australia.
    Donne, Scott W.
    Nitrogen Doped Heat-Treated and Activated Hydrothermal Carbon: examination of Electrochemical Performance Using Step Potential Electrochemical Spectroscopy2018In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 165, no 11, p. A2840-A2848Article in journal (Refereed)
    Abstract [en]

    Step potential electrochemical spectroscopy (SPECS) has been applied to nitrogen-doped and non-doped hydrothermal carbons that have been activated or heat-treated at a range of temperatures. The highest surface area achieved was 422 m(2).g(-1) under heat-treatment at 600 degrees C, and 2275 m(2).g(-1) using H3PO4 chemical activation at 800 degrees C. The heat-treated series reported a maximum capacitance of 84 F.g(-1) at 10 mV.s(-1), whereas the activated series had a maximum capacitance of 306 F.g(-1) at 10 mV.s(-1) . SPECS analysis revealed that pseudo-capacitance for the hydrothermal carbon doped with nitrogen was interlinked with the degree of oxygen functionality, and that decreasing the oxygen content of the surface increased the pseudo-capacitance contribution from nitrogen. Pseudo-capacitance also increased with activation from the incorporation of phosphate groups; however, the nitrogen-doped hydrothermal carbons displayed minimal double-layer capacitance (60.6 F.g(-1) at 10 mV.s(-1)) despite having reasonable surface areas (1500-1600 m(2).g(-1)).

  • 162.
    Le Bozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Joiret, Suzanne
    CNRS, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    The role of chromate conversion coating in the filiform corrosion of coated aluminum alloys2003In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, no 12, p. B561-B566Article in journal (Refereed)
    Abstract [en]

    The mechanisms of inhibition of chromate conversion coating on the filiform corrosion of coated aluminum alloy AA6016 was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and Raman microspectroscopy. The results showed that Cr(VI) was preferably leached out at the opening of the filament, whereas Cr(VI) was reduced to Cr(III) at all other locations. The leached out Cr(VI) accumulated mainly in the pitting area, located in the scratch just outside the filament. The chromate released from the CCC was partly reduced to Cr(III) in the pit. The formation of an Al/Cr mixed oxide was observed in the pitting area. The repassivation of pits in the scratch by the chromate leaching from the CCC close to the scratch explains the low propagation of filiform corrosion observed for the chromated surfaces.

  • 163.
    Le, Thanh-Tung
    et al.
    Shanghai Univ, Peoples R China.
    Huang, Shoushuang
    Shanghai Univ, Peoples R China.
    Ning, Ping
    Shanghai Univ, Peoples R China.
    Wang, Wenwen
    Shanghai Univ, Peoples R China.
    Wang, Qing
    Shanghai Univ, Peoples R China.
    Jiang, Yong
    Shanghai Univ, Peoples R China.
    He, Qingquan
    Shanghai Univ, Peoples R China.
    Feng, Jialiang
    Shanghai Univ, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Chen, Zhiwen
    Shanghai Univ, Peoples R China.
    Carbon-Decorated Fe3S4-Fe7Se8 Hetero-Nanowires: Interfacial Engineering for Bifunctional Electrocatalysis Toward Hydrogen and Oxygen Evolution Reactions2020In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 167, no 8, article id 086501Article in journal (Refereed)
    Abstract [en]

    The design and synthesis of complex multi-component heterostructures is an effective strategy to fabricate cost-efficient catalysts for electrochemical water splitting. Herein, one-dimensional porous Fe3S4-Fe7Se8 heterostructured nanowires confined in carbon (Fe3S4-Fe7Se8@C) were synthesized via the selenization of Fe-based organic-inorganic nanowires. Benefiting from the merits of morphology, composition and surface structure characteristics, i.e., the high structural void porosity, the direct electrical pathways of nanowire topology and the conductive carbon layer coating, the titled catalyst not only offered a larger accessible electrocatalytic interface but also facilitated diffusion of the electrolyte and gas. Moreover, the electron redistribution at the Fe3S4-Fe7Se8 heterojunction interfaces reduced the adsorption free-energy barriers on the active sites, endowing the catalysts with faster reaction kinetics and improved electrocatalytic activity. Accordingly, the optimal Fe3S4-Fe7Se8@C produced a low hydrogen evolution reaction overpotential of 124 mV at 10 mA cm (-2) with a Tafel slope of 111.2 mV dec(-1), and an ultralow oxygen evolution reactions overpotential of 219 mV at 20 mA cm (-2 ), respectively. When applied as both anode and cathode for overall water splitting, a low battery voltage of 1.67 V was achieved along with excellent stability for at least 12 h. The work presented here offered a feasible scheme to fabricate non-noble metal-based electrocatalysts for water splitting. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.

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  • 164.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    In situ studies of the initiation and propagation of filiform corrosion on aluminum2004In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 151, no 7, p. B440-B445Article in journal (Refereed)
    Abstract [en]

    We have investigated the initiation and propagation of filiform corrosion on coated aluminum surfaces using a new experimental set-up for in situ Fourier transform infrared (FTIR) microspectroscopy and the scanning Kelvin probe. During the initiation partially hydrolyzed aluminum chloride was formed in a defect on the coated surface. The conditions in the defect resembled the environment that is found in growing pits with low pH and high chloride concentration close to the coating interface. This weakened the adhesion of the organic coating and initiated the formation of a filament. The movement .of the active head was followed with in situ FTIR microspectroscopy in humid air using the characteristic IR band around 2500 cm-1 from Al(H 2O)6 3+. This band is present in spectra from partially hydrolyzed aluminum chloride, which was found in the head during propagation of the filament. The absorption of water in the hygroscopic corrosion products in the head of the filament was followed by measuring the changes in the intensity of the Al(H2O)6 3+ band during variations in the relative humidity. The hygroscopic properties of the aluminum hydroxy chloride salts formed in the head have important consequences for filiform corrosion, especially concerning the influence of climatic parameters such as the relative humidity and the effect of wet/dry transitions on the propagation of filiform corrosion.

  • 165.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Dan
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Stoulil, J.
    VSCHT, Czech Republic.
    Atmospheric corrosion of zinc-aluminum alloyed coated steel in depleted carbon dioxide environments2018In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 165, no 7, p. C343-C353Article in journal (Refereed)
    Abstract [en]

    NaCl induced corrosion of Zn-0.2Al, Zn-5Al and Zn-55Al coated steel was investigated at low and ambient CO2 levels.Weight loss measurements revealed an enhancement of the corrosion of Zn-0.2Al and particularly Zn-5Al in low CO2. This was connected to an increase of surface pH in a low CO2 atmosphere promoting the formation of ZnO and layered double hydroxide for Zn-5Al. For Zn-55Al, CO2 depletion did not affect the surface pH due to the acidification effect of Al3+. Preferential dissolution of zinc rich phase was observed on cross-sections, particularly in depleted CO2 experiments. Different sequences of corrosion product formation were proposed for the different Zn-Al coatings. © The Author(s) 2018. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/),

  • 166.
    Leijonmarck, Simon
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Danielsson, Carl-Ola
    Stora Enso, Karlstad Research Centre.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Electrochemical characterization of electrically induced adhesive debonding2011In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 158, no 10, p. P109-P114Article in journal (Refereed)
    Abstract [en]

    This study concerns with controlled debonding of adhesive generated with electricity. This is a concept which could potentially be used in a wide range of applications, such as light-weight automotives, which can be easily recyclable at the touch of a button. The studied material is produced as a laminate with an epoxy adhesive bonded between aluminium foils. An electrochemical investigation of these debonding adhesives was performed. A three-electrode system with a circular quasi-reference electrode was validated and used together with electrical impedance spectroscopy and scanning electron microscope. It was found that the resistance at the debonding anodic interface of the laminate increased during polarization. This increase in resistance was shown to be reversible at open circuit. During the polarization, aluminium compounds were produced at the anode. These compounds grew to penetrate the adhesive. A debonding mechanism based on increasing mechanical stresses at the anodic interface is proposed.

  • 167.
    Leone, Stefano
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Henry, Anne
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Andersson, Sven
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Kordina, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Janzén, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Optimization of a Concentrated Chloride-Based CVD Process for 4H–SiC Epilayers2010In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, no 10, p. H969-H979Article in journal (Refereed)
    Abstract [en]

    Concentrated homoepitaxial growths of 4H–SiC was performed using a chloride-based chemical vapor deposition (CVD) process on different off-angle substrates (on-axis, 4 and 8° off-axis toward the [110] direction). A suitable combination of gas flow and process pressure is needed to produce the gas speed that yields an optimum cracking of the precursors and a uniform gas distribution for deposition over large areas. The use of low pressure and the addition of chlorinated precursors bring the added benefit of achieving higher growth rates. A systematic study of the gas speed's effect on the growth rate, uniformity, and morphology on the 4H–SiC epitaxial layers was performed. Growth rates in excess of 50  µm/h were achieved on 50 mm diameter wafers with excellent thickness uniformity (below 2% /mean without rotation of the substrate) and smooth morphology using only 1/10 of the typical gas carrier flow and process pressure demonstrating the feasibility of a concentrated chloride-based CVD process for 4H–SiC. Thermodynamic calculations showed that the improved thickness uniformity could be due to a more uniform gas phase composition of the silicon intermediates. The concentration of the SiCl2 intermediate increases by a factor of 8 at a reduced carrier flow, while all the other hydrogenated silicon intermediates decrease.

  • 168.
    Li, Jing
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ecco, Luiz
    University of Trento, Italy.
    Ahniyaz, Anwar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Fedel, Michele
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    In situ AFM and electrochemical study of a waterborne acrylic composite coating with CeO2 nanoparticles for corrosion protection of carbon steel2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 10, p. C610-C618Article in journal (Refereed)
    Abstract [en]

    The corrosion protection of a waterborne acrylic composite coating with 1 wt% ceria nanoparticles (CeNP) coated on carbon steel in 3 wt% NaCl solution was investigated by ex-situ and in situ as well as electrochemical atomic force microscopy (AFM) observations, combined with open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The synthesized CeNP were stabilized by acetic acid. The transmission electron microscopy characterization showed fine nano-size of as-synthesized CeNP, the ex-situ AFM imaging revealed uniform dispersion of the CeNP in the composite coating and greatly reduced nano-sized pinholes in the coating. The in situ and electrochemical (EC) AFM investigations indicate release of some CeNP and aggregates from the coating surface and then precipitation of some particles and cerium-compounds during the exposure. The OCP and EIS results demonstrated that the addition of 1 wt% CeNP leads to a significantly improved long term barrier type corrosion protection of the waterborne acrylic composite coating for carbon steel in 3 wt% NaCl solution. The beneficial effect of the CeNP is attributed to the blocking of nano-sized defects and inhibition by the cerium compounds originated from the acetic acid stabilized CeNP.

  • 169.
    Li, Jing
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Ecco, Luiz
    Ahniyaz, Anwar
    Fedel, Michele
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    In Situ AFM and Electrochemical Study of a Waterborne Acrylic Composite Coating with CeO2 Nanoparticles for Corrosion Protection of Carbon Steel2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 10, p. C610-C618Article in journal (Refereed)
    Abstract [en]

    The corrosion protection of a waterborne acrylic composite coating with 1 wt% ceria nanoparticles (CeNP) coated on carbon steel in 3 wt% NaCl solution was investigated by ex-situ and in situ as well as electrochemical atomic force microscopy (AFM) observations, combined with open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The synthesized CeNP were stabilized by acetic acid. The transmission electron microscopy characterization showed fine nano-size of as-synthesized CeNP, the ex-situ AFM imaging revealed uniform dispersion of the CeNP in the composite coating and greatly reduced nano-sized pinholes in the coating. The in situ and electrochemical (EC) AFM investigations indicate release of some CeNP and aggregates from the coating surface and then precipitation of some particles and cerium-compounds during the exposure. The OCP and EIS results demonstrated that the addition of 1 wt% CeNP leads to a significantly improved long term barrier type corrosion protection of the waterborne acrylic composite coating for carbon steel in 3 wt% NaCl solution. The beneficial effect of the CeNP is attributed to the blocking of nano-sized defects and inhibition by the cerium compounds originated from the acetic acid stabilized CeNP.

  • 170.
    Li, Jing
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Ecco, Luiz
    Delmas, Gregory
    Whitehouse, Nigel
    Collins, Peter
    Deflorian, Flavio
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    In-Situ AFM and EIS Study of Waterborne Acrylic Latex Coatings for Corrosion Protection of Carbon Steel2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 1, p. C55-C63Article in journal (Refereed)
    Abstract [en]

    Corrosion protection for carbon steel by three waterborne styrene-acrylic latex coatings with different glass transition temperature (Tg) and levels of hydrophobicity has been studied by in-situ atomic force microscope (AFM) and electrochemical impedance spectroscopy (EIS) measurements in 3.0 wt% NaCl solution. The AFM images reveal the micro-and nano-structure of and pinholes in the coatings as well as their changes during exposure in the solution, whereas the EIS spectra vs. time of exposure show the barrier property, stability and degradation of the coatings. The coating with crosslinking and high level of hydrophobicity exhibited a high barrier property and long-term corrosion protection in the solution despite of some shallow pinholes. The coating without crosslinking but having high Tg and high level of hydrophobicity also displayed a high barrier property and certain stability although initial changes occur in the solution. However, for the coating without crosslinking and with low Tg and relative low level of hydrophobicity, some dissolution and open-up of defects occurred on the surface shortly after exposure and the coating lost its barrier property rapidly in the solution. The reasons for the different behaviors between the coatings are discussed with respect to the crosslinking, Tg and the hydrophobicity level of the coating.

  • 171.
    Li, Mingyu
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Naureen, Shagufta
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Shahid, Naeem
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Anand, Srinivasan
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Fabrication of Submicrometer InP Pillars by Colloidal Lithography and Dry Etching2010In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, no 9, p. II896-II899Article in journal (Refereed)
    Abstract [en]

    A simple method for the fabrication of submicrometer InP pillars with large surface area coverage has been developed based on a combination of colloidal lithography and inductively coupled plasma (ICP) etching technique using Cl-2/H-2/CH4/Ar chemistry. Pillars with different sizes could be fabricated by using colloidal SiO2 particles with different sizes dispersed on the sample serving as masks. Pillars with lateral diameters as small as 60 nm and aspect ratios as high as 10: 1 have been obtained. The effects of etch parameters such as radio-frequency power, ICP power, and etching time on pillar fabrication are investigated. By a suitable choice of etch parameters and utilizing erosion of colloidal (mask) SiO2 particle during etching, the height of the pillars as well as their shape can be modified from nearly cylindrical to conical shapes. Such a control on the shape of the structures in addition to the large surface coverage could be useful for applications in photovoltaics and for the fabrication of photonic crystals. For instance, continuous grading of the refractive index can be obtained for surfaces covered with conical pillars, which can be used as antireflecting surfaces in solar cells or for light extraction in light emitting diodes.

  • 172.
    Lindbergh, Göran
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Olivry, Marie
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Sparr, Mari
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Experimental Investigation of the Porous Nickel Anode in the Molten Carbonate Fuel Cell2001In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 148, no 5, p. A411-A417Article in journal (Refereed)
    Abstract [en]

    The electrochemical performance of the porous nickel anode in a molten carbonate fuel cell was experimentally investigated in this study. The electrode structure was studied by scanning electron microscope and Hg porosimetry. The effect of electrolyte filling, on overpotential at a constant current density, was also examined. Kinetics for the hydrogen reaction was studied by obtaining stationary polarization curves, for porous nickel anodes at varying temperatures and anode gas compositions. The slopes of these polarization curves were analyzed at low overpotentials, with the assumption that the porous anode was under kinetic control, and the corresponding exchange current densities were determined using a simplified porous electrode model. The obtained partial pressure dependencies of the exchange current density were high, and therefore, difficult to explain by the generally assumed mechanisms.

  • 173. Lindström, Rakel
    et al.
    Johansson, L. G.
    Svensson, J. E.
    The influence of NaNO3 on the atmospheric corrosion of zinc2003In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, no 12, p. B583-B588Article in journal (Refereed)
    Abstract [en]

    The influence of NaNO3 salt deposits on the atmospheric corrosion of zinc in humid air has been studied. Comparisons are made with the effects of NaCl and Na2SO4. Also the combined effect of NaNO3 with NaCl or Na2SO4 was investigated. The salts were applied to zinc samples prior to exposure. The samples were exposed to purified humid air with careful control of relative humidity (95%), temperature (22.0degreesC), and flow conditions. The CO2 concentration was 350 ppm and the exposure time was 4 weeks. Mass gain and metal loss results are reported. The corrosion products were analyzed by gravimetry, ion chromatography, and X-ray diffraction. Results show that the corrosion rate in the presence of NaNO3 is only a third of that registered in the presence of NaCl and Na2SO4. Further, a slight inhibitive effect of NaNO3 was found in the presence of NaCl or Na2SO4. The decreased corrosion rate in the presence of NaNO3 was attributed to the reduction of nitrate to nitrite at the zinc surface. Nitrite is suggested to act as a corrosion inhibitor toward zinc.

  • 174. Lindström, Rakel
    et al.
    Svensson, J. E.
    Johansson, L. G.
    The atmospheric corrosion of zinc in the presence of NaCl the influence of carbon dioxide and temperature2000In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 147, no 5, p. 1751-1757Article in journal (Refereed)
    Abstract [en]

    The atmospheric corrosion of zinc has been studied at 4, 22, and 38 degrees C. The samples were exposed to synthetic air with careful control of CO2 concentration, relative humidity, and flow conditions. The relative humidity was 95%, and the concentrations of CO2 were <1 and 350 ppm, respectively. Sodium chloride was added before the exposures (0, 14. and 70 mu g/cm(2)). Mass gain and metal loss results are reported. As expected, NaCl is corrosive toward zinc, giving rise to heavy pitting. In the absence of CO2, the rare of the NaCl-induced corrosion was found to increase strongly with temperature. However, in the presence of CO2, the corrosion rate of zinc is independent of temperature. In the absence of CO2. zincite, ZnO, is the dominant corrosion prod;ct, while zinc hydroxy carbonates and simonkolleite, Zn-5(OH)(8)Cl-2. H2O, dominate in the presence of CO2. A mechanism is presented that explains the observations.

  • 175. Lindström, Rakel
    et al.
    Svensson, J. E.
    Johansson, L. G.
    The influence of carbon dioxide on the atmospheric corrosion of some magnesium alloys in the presence of NaCl2002In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 149, no 4, p. B103-B107Article in journal (Refereed)
    Abstract [en]

    The influence of ambient concentrations of carbon dioxide on the NaCl-induced atmospheric corrosion of high purity die-cast MgAl alloys (AM20 and AM60) and MgAlZn alloy (AZ91) is reported. Samples were exposed four weeks in a carefully controlled synthetic atmosphere. Relative humidity was 95%, the temperature was 22.0degreesC, and the concentration of CO2 was <1 or 350 ppm. Sodium chloride was added before the exposures (70 μg/cm(2)). The corrosion products were analyzed by gravimetry, ion chromatography, X-ray diffraction, and environmental scanning electron microscopy. Mass gain and metal loss results are reported. As expected, the combination of high humidity and NaCl is very corrosive toward the magnesium alloys investigated. The NaCl-induced corrosion is inhibited by ambient concentrations of CO2. Exposures in the absence of CO2 give rise to heavy pitting; Mg(OH)(2), brucite, is the dominant corrosion product. In the presence of CO2, a uniform layer of hydrated magnesium hydroxy carbonate, Mg-5 (CO3)(4) (OH)(2)&BULL;5H(2)O, forms. In both environments, the corrosion rates increased in the order AZ91, AM60, AM20.

  • 176. Lindström, Rakel
    et al.
    Svensson, J. E.
    Johansson, L. G.
    The influence of salt deposits on the atmospheric corrosion of zinc - The important role of the sodium ion2002In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 149, no 2, p. B57-B64Article in journal (Refereed)
    Abstract [en]

    The influence of salt deposits on the atmospheric corrosion of zinc was studied in the laboratory. Four chloride-containing salts, NaCl, NH4Cl, ZnCl2, and MgCl2, and four sulfate-containing salts, Na2SO4,(NH4)(2)SO4, ZnSO4, and MgSO4, were investigated. The salts were applied by spraying a saturated ethanol/water solution before exposure. The samples were exposed to purified humid air with careful control of relative humidity (95%), temperature (22.0degreesC), and air flow. The concentration of CO2 was 350 ppm and the exposure time was four weeks. The salts formed aqueous solutions on the metal surface. Mass gain and metal loss results are reported. The corrosion products were analyzed by gravimetry, ion chromatography, and X-ray diffraction. It was concluded that zinc corrodes by an electrochemical mechanism. Of the four cations studied, sodium was by far the most corrosive toward zinc. The corrosion of zinc was directly correlated with the amount of sodium ion and did not depend on whether Na2SO4 or NaCl was added. The comparatively rapid corrosion caused by the two sodium salts is suggested to be due to the absence of insoluble sodium compounds. In contrast, the divalent cations precipitate in the cathodic areas due to the high pH values produced, resulting in the blocking of the cathodic sites.

  • 177.
    Liu, Min
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. University of Science and Technology Beijing, National Center for Materials Service Safety.
    Jin, Ying
    University of Science and Technology Beijing, National Center for Materials Service Safety.
    Leygraf, Christofer
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    A DFT-Study of Cl Ingress into α-Al2O3(0001) and Al(111) and Its Possible Influence on Localized Corrosion of Al2019In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 166, no 11, p. C3124-C3130Article in journal (Refereed)
    Abstract [en]

    Ingress of chloride into alpha-Al2O3(0001) and Al(111) was calculated by first-principles theory calculations by considering Cl insertion into Al or O vacancies within alpha-Al2O3(0001) or into vacancy or interstitial sites within Al(111). For alpha-Al2O3, the formation of an O vacancy is energetically more favorable than of an Al vacancy. The insertion of Cl into an O vacancy is also more favorable than into an Al vacancy. A high energy-barrier has been derived for Cl transport within the neighboring O vacancies. In addition, the work function decreases with Cl ingress into the interior of the oxide. For Al(111), Cl insertion into either an Al vacancy or an interstitial site is less favorable compared to the insertion into alpha-Al2O3. The work function only changes slightly with Cl insertion into an Al vacancy. Moreover, the pre-inserted Cl reduces the energy-barrier for further Cl ingress into alpha-Al2O3, whereas Cl tends to stay in the sub-surface layer of Al(111), suggesting Cl accumulation at the Al2O3/Al.

  • 178. Ljungberg, K.
    et al.
    Söderberg, A.
    Tiensuu, A-L
    Johansson, S.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    Petersson, Sture
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    Buried Cobalt Silicide Layers in Silicon Created by Wafer Bonding1994In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 141, no 10, p. 2829-2833Article in journal (Refereed)
    Abstract [en]

    A buried conductive layer in silicon has been created using wafer bonding technique, with a cobalt interfacial layer.Co-coated silicon wafers were brought into contact with either similar or uncoated wafers at room temperature. CoSi2 wasthen formed through a solid-phase reaction, during an anneal at 700 to 900°C. A 700 Å buried CoSi2-layer, with a resistivityof approximately 21 µ cm, was achieved. Good adhesion, as measured by tensile strength testing, between the wafers wasachieved. Transmission electron microscopic investigations (Co-coated wafer bonded to bare silicon) showed that thesilicide has not grown into the opposite wafer, and that an amorphous layer exists between the silicide and the siliconsurface. The presence of such a layer has been confirmed by electrical characterization.

  • 179. Ljungberg, K
    et al.
    Söderbärg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bengtsson, S
    Jauhiainen, A
    Characterization of spontaneously bonded hydrophobic silicon surfaces1994In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 141, no 2, p. 562-566Article in journal (Refereed)
  • 180. Ljungberg, K
    et al.
    Söderbärg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Tiensuu, A-L
    Johansson, S
    Thungström, G
    Petersson, S
    Buried cobalt silicide slyers in silicon created by wafer bonding1994In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 141, no 10, p. 2829-2833Article in journal (Refereed)
  • 181.
    Ljungberg, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics.
    Bäcklund, Ylva
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics.
    Söderbärg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics.
    Bergh, M
    Andersson, M O
    Bengtsson, Stefan
    The effects of HF-cleaning prior to silicon wafer bonding1995In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 142, no 4, p. 1297-1303Article in journal (Refereed)
  • 182. Ljungberg, Karin
    et al.
    Söderbärg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bengtsson, S
    Jauhiainen, A
    Characterization of spontaneously bonded hydrophobic silicon surfaces1993In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111Article in journal (Refereed)
  • 183.
    Lofgren, P.M.
    et al.
    ABB Corporate Research, S-721 78 Väterås, Sweden, Faxén Laboratory, Royal Institute of Technology, S-100 44 Stockholm, Sweden.
    Ji, W.
    ABB Corporate Research, S-721 78 Väterås, Sweden.
    Hallin, C.
    Gu, C.-Y.
    ABB Corporate Research, S-721 78 Väterås, Sweden.
    Modeling of silicon carbide epitaxial growth in hot-wall chemical vapor deposition processes2000In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 147, no 1, p. 164-175Article in journal (Refereed)
    Abstract [en]

    A complete two-dimensional axisymmetric model for chemical vapor deposition (CVD) is presented, incorporating reduction heating by a radio frequency coil, flow, heat transfer (radiation included), and gas and surface chemistry, applied to epitaxial growth of silicon carbide (SiC) with H2 as the carrier gas and C3H8 and SiH4 as precursors. Temperatures range from 1873 to 1923 K. Predictions are compared to full-scale experiments carried out in the Linkoping hot-wall CVD reactor for epitaxial growth. Temperature predictions have previously shown to agree well with experiments, consequently, this paper focuses on the reaction mechanism model. Three different reaction mechanisms are compared to experiments where mechanisms contain 35 gas, seven surface, and two bulk species including gas and surface reactions. The predicted growth rate agrees well with experiments for 300 mbar but is slightly low for 50 mbar and somewhat high for 550 mbar. By including a recent mechanism for decomposition of SiH4, morphological conditions can be predicted comparing partial pressures of Si and C2H2 to experimental data from the literature. The predicted growth rate is not influenced by this additional model. It is demonstrated that when a model for hydrogen etching of the susceptor graphite is included, correct growth limitation is predicted.

  • 184. Lucht, Brett L.
    et al.
    Guyomard, Dominique
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Kostecki, Robert
    Electrochemical Interfaces in Electrochemical Energy Storage Systems2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 13, p. Y13-Y13Article in journal (Refereed)
  • 185.
    Lundgren, Henrik
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Behm, Mårten
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Electrochemical Characterization and Temperature Dependency of Mass-Transport Properties of LiPF6 in EC:DEC2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 3, p. A413-A420Article in journal (Refereed)
    Abstract [en]

    Mass transport in the electrolyte is one of the limiting processes when it comes to the power density and energy efficiency of lithium-ion batteries. Electrolyte characterizations are therefore of utmost importance. This study reports the ionic conductivity, diffusion coefficient, lithium-ion transport number, and thermodynamic enhancement factor, as well as density and viscosity, for the electrolyte LiPF6 in EC:DEC (1 1, by weight) at 10 degrees C, 25 degrees C, and 40 degrees C and for concentrations between 0.5 M and 1.5 M. By combining mathematical modeling and three experiments: conductivity measurements, concentration cells, and galvanostatic polarizations, the mass transport phenomena were fully characterized. All parameters were found to vary strongly with both concentration and temperature proving that temperature dependent parameters are essential when studying thermal behavior of lithium-ion batteries. Moreover, conductivity increased with temperature and showed a local maximum at around 1 M within the concentration range at all temperatures. The other parameters either showed a continuous decrease (diffusion coefficient and lithiumion transport number) or increase (thermodynamic enhancement factor) with concentration at all temperatures. Limited liquid range leading to solvent crystallization at 10 degrees C leads to very poor performance, possibly due to the strong coordination between the lithium ion and the crystallizing species, EC. Overall, the studied electrolyte is found to perform poorly compared to previously studied systems.

  • 186.
    Lundgren, Henrik
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Scheers, Johan
    Behm, Mårten
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Characterization of the Mass-Transport Phenomena in a Superconcentrated LiTFSI: Acetonitrile Electrolyte2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 7, p. A1334-A1340Article in journal (Refereed)
    Abstract [en]

    Superconcentration of aprotic electrolytes has recently emerged as a way to stabilize solvents that otherwise would be impossible to use, in e.g. lithium-ion batteries (LIBs). As demanding applications, such as hybrid electric vehicles and fast charging, become increasingly important, battery manufacturers are struggling to find a suitable electrolyte able to deliver high power with low polarization. Electrolyte characterizations able to accurately predict the high-power performance of such electrolytes are also of utmost importance. This study reports a full.characterization of the mass-transport phenomena for a superconcentrated LiTFSL-acetonitrile electrolyte in concentrations ranging from 2.7 M to 4.2 M. The method obtains the ionic conductivity, cationic transport number, diffusion coefficient, and the thermodynamic enhancement factor, by combining mathematical modeling and three electrochemical experiments. Furthermore, the density and the viscosity were measured. The transport number with respect to the room is found to be very high compared to other liquid LIB electrolytes, but a low diffusion coefficient lowers overall performance. The ionic conductivity decreases quickly with concentration, dropping from 12.7 mS/cm at 2.7 M to 0.76 mS/cm at 4.2 M. Considering all the effects in terms of the mass-transport of the electrolyte, the lower end of the studied concentration range is favorable.

  • 187.
    Lundgren, Henrik
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Svens, Pontus
    Ekström, Henrik
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Tengstedt, Carl
    Lindström, Johan
    Behm, Mårten
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Thermal Management of Large-Format Prismatic Lithium-Ion Battery in PHEV Application2016In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 163, no 2, p. A309-A317Article in journal (Refereed)
    Abstract [en]

    Thermal effects are linked to all main barriers to the widespread commercialization of lithium-ion battery powered vehicles. This paper presents a coupled 2D electrochemical - 3D thermal model of a large-format prismatic lithium-ion battery, including a thermal management system with a heat sink connected to the surface opposite the terminals, undergoing the dynamic current behavior of a plug-in hybrid electric (PHEV) vehicle using a load cycle with a maximum current of 8 C, validated using potential and temperature data. The model fits the data well, with small deviations at the most demanding parts of the cycle. The maximum temperature increase and temperature difference of the jellyroll is found to be 9.7 degrees C and 3.6 degrees C, respectively. The electrolyte is found to limit the performance during the high-current pulses, as the concentration reaches extreme values, leading to a very uneven current distribution. Two other thermal management strategies, short side and long side surfaces cooling, are evaluated but are found to have only minor effects on the temperature of the jellyroll, with maximum jellyroll temperatures increases of 9.4 degrees C and 8.1 degrees C, respectively, and maximum temperature differences of 3.7 degrees C and 5.0 degrees C, respectively.

  • 188.
    Långberg, Marie
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. SWERIM, SE-16407 Kista, Sweden..
    Örnek, Cem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Zhang, Fan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Cheng, J.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Liu, M.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Granaes, E.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Wiemann, C.
    Res Ctr Julich, Peter Grunberg Inst PGI 6, D-52425 Julich, Germany..
    Gloskovskii, A.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Matveyev, Y.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Kulkarni, S.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Noei, H.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Keller, T. F.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Phys Dept, D-20355 Hamburg, Germany..
    Lindell, D.
    SWERIM, SE-16407 Kista, Sweden..
    Kivisakk, U.
    AB Sandvik Mat Technol, SE-81181 Sandviken, Sweden..
    Lundgren, E.
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Stierle, A.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany.;Univ Hamburg, Phys Dept, D-20355 Hamburg, Germany..
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Characterization of Native Oxide and Passive Film on Austenite/Ferrite Phases of Duplex Stainless Steel Using Synchrotron HAXPEEM2019In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 166, no 11, p. C3336-C3340Article in journal (Refereed)
    Abstract [en]

    A new measurement protocol was used for microscopic chemical analysis of surface oxide films with lateral resolution of 1 mu m. The native air-formed oxide and an anodic passive film on austenite and ferrite phases of a 25Cr-7Ni super duplex stainless steel were investigated using synchrotron hard X-ray photoemission electron microscopy (HAXPEEM). Pre-deposited Pt-markers, in combination with electron backscattering diffraction mapping (EBSD), allowed analysis of the native oxide on individual grains of the two phases and the passive film formed on the same area after electrochemical polarization of the sample. The results showed a certain difference in the composition of the surface films between the two phases. For the grains with (001) crystallographic face // sample surface, the native oxide film on the ferrite contained more Cr oxide than the austenite. Anodic polarization up to 1000 mV/(Ag/AgCl) in 1M NaCl solution at room temperature resulted in a growth of the Cr- and Fe-oxides, diminish of Cr-hydroxide, and an increased proportion of Fe3+ species. by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.

  • 189.
    Malmberg, Helena
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Zuleta, Marcelo
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Lundblad, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Björnbom, Pehr
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Ionic transport in pores in activated carbons for EDLCs2006In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 153, no 10, p. A1914-A1921Article in journal (Refereed)
    Abstract [en]

    The transport properties and morphology of an activated carbon containing macro-, meso-, and micropores were studied and compared to a sophisticated fully nanoporous carbon that almost lacks meso- and macropores. The morphology of the activated carbon was studied using nitrogen adsorption methods and the pore size distribution was investigated using Barret, Joyner, and Halenda and density functional theory models. The transport properties were studied using a microelectrode technique that allows for determination of the effective diffusivity, D-eff. For the meso/macroporous carbon the effective diffusivity was determined using potential step experiments and analysis for both Cottrell and filling diffusivities were made. The Cottrell diffusivity was smaller than the value of the filling diffusivity, with mean values of (9.4 +/- 3.8) x 10(-14) m(2) s(-1) and (3.1 +/- 1.6) x 10(-12) m(2) s(-1), respectively. This difference in diffusivities is the basis for an agglomerate hypothesis presented for the meso/macroporous carbon. The results for the meso/macroporous carbon are compared with the corresponding results for the sophisticated fully nanoporous carbon. This gave further evidence for the presented agglomerate hypothesis.

  • 190.
    Mandal, Sudip
    et al.
    Indian Inst Technol Madras, India.
    Suriyanarayanan, Subramanian
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Nicholls, Ian A.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Ramanujam, Kothandaraman
    Indian Inst Technol Madras, India.
    Selective Sensing of the Biotinyl Moiety Using Molecularly Imprinted Polyaniline Nanowires2018In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 165, no 14, p. B669-B678Article in journal (Refereed)
    Abstract [en]

    A chemosensor for selective recognition of biotinyl moiety has been devised using electropolymerized film and tested against selective biotinylated targets. The sensor comprises biotin molecularly imprinted polymer (MIP) polymeric nanowires, as a recognition element, overlaid on gold-coated quartz transducers. The preparation of nanostructured MIPs and reference systems have been demonstrated using electrochemical copolymerization of the stabilized complex between the template (biotin), the functional monomer (4-aminobenzoic acid), and cross-linker (aniline) and/or sacrificial biotin-modified Al2O3 membrane. Density functional theoretical studies signify formation of a stable hydrogen-bonded complex of biotin with 4-aminobenzoic acid in the pre-polymerization mixture. Scanning electron microscope studies revealed uniformly grown and densely packed polyaniline hierarchical structures. Piezoelectric microgravimetry under flow injection analysis (FIA) conditions revealed selective binding of biotin methyl ester (BtOMe, 4) (79.89 +/- 2.17 Hz/mM) with imprinted polyaniline hierarchical structures over 10 fold higher than the non-imprinted counterpart. The detection limit of the MIP is 50 nM under optimized conditions. Particularly, the sensor selectively recognizes BtOMe from structural or functional analogues, such as thiamine (4.87 +/- 0.10 Hz/mM) and pyridoxamine (12.08 +/- 0.24 Hz/mM). Importantly, the MIP hierarchical structures were shown to be selective for biotinylated targets (biotin moiety labeled cytochrome C, dextran, oxytocin and obestatin). (C) 2018 The Electrochemical Society.

  • 191.
    Manessis, Dionissios
    et al.
    Department of Materials Science and Engineering, Stevens Institute of Technology, Hoboken, NJ.
    Du, Honghua
    Department of Materials Science and Engineering, Stevens Institute of Technology, Hoboken, NJ.
    Larker, Richard
    Luleå tekniska universitet.
    Oxidation studies of silicon oxynitride ceramics1998In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 145, no 4, p. 1355-1360Article in journal (Refereed)
    Abstract [en]

    Silicon oxynitride ceramics free from sintering aids were oxidized in oxygen-argon and oxygen-nitrogen gas mixtures with varying oxygen and nitrogen partial pressures in the range of 1000 to 1300 °C. Oxidation kinetics of Si2N2O followed a parabolic rate law with activation energies ranging from 43 to 52 kcal/mol. The parabolic rate constants for Si2N2O exhibited a linear dependence on the oxygen partial pressure but no dependence on the nitrogen partial pressure. These findings, in conjunction with our established knowledge of the oxide and interface characteristics of oxidized samples, suggested that molecular oxygen diffusion through SiO2 plays a predominant role in the rate-limiting process for the oxidation of Si2N2O

  • 192.
    Mazinanian, Neda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Hedberg, Yolanda
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. Karolinska Institutet, Sweden.
    Metal Release Mechanisms for Passive Stainless Steel in Citric Acid at Weakly Acidic pH2016In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 163, no 10, p. C686-C693Article in journal (Refereed)
    Abstract [en]

    Metal release investigations from stainless steel into citric acid (CA) solutions at near-neutral pH are relevant for food applications, cleaning, and passivation. This study investigated metal release from abraded stainless steel grade AISI 304 into 5 g/L CA at pH 3.1, 4.8, and 6.4 at 40°C, as compared to a control solution (10 mM KNO3). Polyacrylic acid (PAA) was used as a model solution with and without separation from the stainless steel surface by a membrane. No significant difference was found for the released amounts of Fe and Mn between CA, PAA, and KNO3 solutions at pH 3.1, suggesting other mechanisms than complexation. At pH 4.8 and 6.4, a significantly higher release was found for CA and PAA solutions compared with KNO3 solution, but not for PAA solution when PAA molecules could not reach the stainless steel surface due to membrane separation, implying a dominant complexation-induced metal release mechanism that requires adsorption and/or close vicinity of the complexing agent to the surface. Cr was enriched in the surface oxide (surface passivation) in complexing solutions and the release of Cr was most dependent on complexation by CA at pH 4.8 and 6.4.

  • 193.
    Mellgren, Niklas
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Brown, Shelley
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Vynnycky, Michael
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Impedance as a Tool for Investigating Aging in Lithium-Ion Porous Electrodes: I. Physically Based Electrochemical Model2008In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 155, no 4, p. A304-A319Article in journal (Refereed)
    Abstract [en]

    Electrochemical impedance spectroscopy is potentially a powerful diagnostic tool for the investigation of the effects of aging in porous electrodes. A physically based three-electrode model was developed for a LixNi0.8Co0.15Al0.05O2 composite porous electrode with three porous separators and a reference electrode between a current collector and a plane electrode. Two effects of aging were modeled for this particular electrode chemistry, namely, a resistive corrosion layer on the current collector and a contact resistance between the electronic conductor and the active material of the porous electrode. The derivation of an analytical solution for the impedances between each pair of electrodes in this model yielded a computationally fast, versatile, and modular formulation. The solution was used to study the impact of selected components of the physical model on the impedance spectrum of the porous electrode for a physically relevant base case. Approximating the active material particles as spherical or flake-shaped particles, lognormally or Dirac distributed in size, revealed that the distribution has a negligible impact while the shape makes a noticeable difference. The main aging-related parameters were shown to have quite distinct effects on the impedance spectrum, which is essential for the regression of experimental data and the study of aging hypotheses.

  • 194.
    Menon, C.
    et al.
    Department of Microelectronics, Royal Institute of Technology (KTH), Electrum 229, SE-164 40 Kista, Sweden.
    Lindgren, A.-C.
    Department of Microelectronics, Royal Institute of Technology (KTH), Electrum 229, SE-164 40 Kista, Sweden.
    Persson, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Hultman, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Radamson, H.H.
    Department of Microelectronics, Royal Institute of Technology (KTH), Electrum 229, SE-164 40 Kista, Sweden.
    Selective epitaxy of Si1-xGex layers for complementary metal oxide semiconductor applications2003In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, no 4Article in journal (Refereed)
    Abstract [en]

    The selective growth of Si-buffer/Si1-xGex/Si-cap structures (0.14 < × < 0.33) on patterned substrates aimed for channel layer applications in a metal-oxide-semiconductor field effect transistor structure was investigated. By optimizing the growth parameters the surface roughness of these structures was reduced. Furthermore, selective epitaxy of high B- or P-doped SiGe layers for source/drain applications was also studied. Abrupt dopant profiles with a good epitaxial quality and low sheet resistance, e.g., 195 and 260 O/? for 420 Å thick, B-doped Si0.81Ge0.19 and P-doped Si0.71Ge0.29 layers, respectively, were obtained. In this study, secondary ion mass spectroscopy, high-resolution reciprocal lattice mapping, atomic force microscopy, and cross-sectional transmission electron microscopy were used as the main characterization tools.

  • 195. Menon, C
    et al.
    Lindgren, AC
    Persson, POA
    Hultman, L
    Radamson, Henry H.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Selective epitaxy of Si1-xGex layers for complementary metal oxide semiconductor applications2003In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, no 4, p. G253-G257Article in journal (Refereed)
    Abstract [en]

    The selective growth of Si-buffer/Si1-xGex/Si-cap structures (0.14 < x < 0.33) on patterned substrates aimed for channel layer applications in a metal-oxide-semiconductor field effect transistor structure was investigated. By optimizing the growth parameters the surface roughness of these structures was reduced. Furthermore, selective epitaxy of high B- or P-doped SiGe layers for source/drain applications was also studied. Abrupt dopant profiles with a good epitaxial quality and low sheet resistances, e.g., 195 and 260 Omega/square for 420 Angstrom thick, B-doped Si0.81Ge0.19 and P-doped Si0.71Ge0.29 layers, respectively, were obtained. In this study, secondary ion mass spectroscopy, high-resolution reciprocal lattice mapping, atomic force microscopy, and cross-sectional transmission electron microscopy were used as the main characterization tools.

  • 196. Messmer, E. R.
    et al.
    Soderstrom, D.
    Hult, P.
    Marcinkevicius, Saulius
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Look, D. C.
    Properties of semi-insulating GaAs: Fe grown by hydride vapor phase epitaxy2000In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 147, no 8, p. 3109-3110Article in journal (Refereed)
    Abstract [en]

    In this paper we analyze GaAs grown by hydride vapor phase epitaxy (HVPE) and doped with four different iron concentrations between 4 X 10(16) and 4.5 X 10(20) cm(-3). From temperature dependent current-voltage measurements we observed the highest resistivity in the lowest doped sample. We also quantified the activation energy. These results together with those of time resolved photoluminescence measurements indicate that in the sample with the lowest Fe concentration, EL2 may be dominant. From the analysis of the time resolved photoluminescence measurements, the intrinsic EL2 concentration and the electron and hole capture cross sections of Fe in GaAs were estimated.

  • 197.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Yofis, S.
    Technion Israel Institute Technology, Israel.
    Salzman, J.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Cohen-Hyams, T.
    Technion Israel Institute Technology, Israel.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    A Nonvolatile Memory Capacitor Based on a Double Gold Nanocrystal Storing Layer and High-k Dielectric Tunneling and Control Layers2010In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, no 4, p. H463-H469Article in journal (Refereed)
    Abstract [en]

    We present a metal-insulator-semiconductor nonvolatile memory capacitor based on two gold nanoparticle charge storage layers, two HfO(2) layers, and a multilayer HfNO/HfTiO stack. The device exhibits an equivalent oxide thickness of 7.3 nm, a hysteresis of 15 V at a gate voltage of +11 to -8 V, and a storage charge density of 2.75x10(13) cm(-2). A leakage of 3.6x10(-5) A/cm(2) at -10 V, a breakdown voltage of 13.3 V, and good retention properties with a hysteresis window of 10 V following more than 10 h of consecutive write/erase operations with a +/- 7 V swing were demonstrated. The capacitor characteristics are frequency-independent in the 10 kHz-1 MHz range.

  • 198. Morcillo, M.
    et al.
    Chico, B.
    de la Fuente, D.
    Aicantara, J.
    Odnevall Wallinder, Inger
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Leygraf, Christopher
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    On the Mechanism of Rust Exfoliation in Marine Environments2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 2, p. C8-C16Article in journal (Refereed)
    Abstract [en]

    Based on exposures in chloride-rich field and laboratory atmospheres, a mechanism of rust exfoliation of carbon steel is proposed. Key ingredients are structural transformations between main rust phases (goethite, lepidocrocite, spinel oxides and akageneite) during varying exposure conditions and their large difference in molar volume with a factor of five between the most compact and least compact rust phase. Akaganeite transformed to spinel results in volume contraction, lepidocrocite to spinel in volume expansion and in both cases stresses are introduced in the rust multilayer. At sufficiently high chloride deposition rates (similar to 300 mg/m(2).d), the rust multilayer eventually detaches resulting in rust exfoliation.

  • 199.
    Nazarov, Andrej P.
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Prosek, Tomas
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Le Bozec, Nathalie
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Protective action of vanadate at defected areas of organic coatings on zinc2005In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 152, no 7, p. B220-B227Article in journal (Refereed)
    Abstract [en]

    The kinetics of vanadate release from an organic coating and the stability and protective ability of the newly formed vanadate-based films on zinc surfaces have been studied with respect to self-healing ability of vanadate-pigmented organic coatings. The results were compared with those obtained with chromate. The kinetics of vanadate release from a polyester coating was comparable to that of chromate. The methods of X-ray absorption near edge spectroscopy (XANES) and scanning Kelvin probe were used for studying the mechanism of inhibition and the kinetics of vanadate reduction on bare zinc. XANES proved to be a powerful tool for determination of the oxidation state of vanadium in surface films. The experiments showed that vanadate was reduced more rapidly than chromate under the same atmospheric conditions. However, addition of magnesium phosphate resulted in a significantly lower reduction rate of vanadate. The results are discussed in light of the increased adsorption ability of the more negatively charged vanadium(V) species at higher pH, while the oxygen reduction process on zinc is inhibited due to the presence of phosphate. Thus, vanadate in combination with another inhibitor could provide corrosion protection at defects of organic coatings on zinc comparable to that of chromate.

  • 200.
    Nazarov, Andrej
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Vivier, V.
    Sorbonne Universités, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Vucko, Flavien
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Tribollet, B.
    Sorbonne Universités, France.
    Effect of mechanical stress on the properties of steel surfaces: Scanning Kelvin probe and local electrochemical impedance study2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 2, p. C66-C74Article in journal (Refereed)
    Abstract [en]

    The influence of mechanical stress on the electrochemical properties of ferritic steel SAE 1008 and austenitic stainless steel 301LN was studied using Scanning Kelvin Probe and Localized Electrochemical Impedance Spectroscopy (LEIS) techniques. The probe-working electrode Volta potential difference was mapped in situ under load. It was found that the influence of elastic deformation on the potential was small. Plastic deformation decreased the potential of steel by 150–300 mV, whereas the relaxation of the load from the plastic domain increased the Volta potential. However, some locations, which can contain residual stress, remained at low potential. The pre-strained surfaces were characterized by X-ray Photo Electronic Spectroscopy and by Atomic Force Microscopy. Distribution of the capacitance across strained and strain-free surfaces was studied by LEIS in boric/borate electrolyte. The plastic stress increases the capacitance and decreases the ability of the steels to passivate the surface indicating that emerging of pile-ups of dislocations create defective oxide films. © The Author(s) 2017.

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