Structure and Bonding in Amorphous Cr1−xCx Nanocomposite Thin Films: X‐ray Absorption Spectra and First-Principles Calculations
2016 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, no 23, 12890-12899 p.Article in journal (Refereed) Published
The local structure and chemical bonding in two-phase amorphous Cr1−xCx nanocomposite thin films are investigated by Cr K-edge (1s) X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies in comparison to theory. By utilizing the computationally efficient stochastic quenching (SQ) technique, we reveal the complexity of different Cr-sites in the transition metal carbides, highlighting the need for large scale averaging to obtain theoretical XANES and EXAFS spectra for comparison with measurements. As shown in this work, it is advantageous to use ab initio theory as an assessment to correctly model and fit experimental spectra and investigate the trends of bond lengths and coordination numbers in complex amorphous materials. With sufficient total carbon content (≥30 at. %), we find that the short-range coordination in the amorphous carbide phase exhibit similarities to that of a Cr7C3 ± y structure, while excessive carbons assemble in the amorphous carbon phase.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016. Vol. 120, no 23, 12890-12899 p.
Inorganic Chemistry Theoretical Chemistry Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-129386DOI: 10.1021/acs.jpcc.6b03608ISI: 000378196200059OAI: oai:DiVA.org:liu-129386DiVA: diva2:938938
Funding agencies:We would like to thank the staff at MAX-lab for experimental support and U. Jansson and M. Andersson for providing the samples. This work was supported by the Swedish Research Council (VR) Linnaeus Grant LiLi-NFM, the FUNCASE project supported Swedish Strategic Research Foundation (SSF). W.O. acknowledges financial support from VR Grant No. 621-2011-4426, the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU No 2009 00971), Knut and Alice Wallenbergs Foundation project Strong Field Physics and New States of Matter 2014-2019 (COTXS). B.A. would like to thank E. Holmstrom and R. Lizarraga for support with the SQ method and acknowledges financial support by the Swedish Research Council (VR) through the young researcher Grant No. 621-2011-4417 and the international career Grant No. 330-2014-6336 and Marie Sklodowska Curie Actions, Cofund, Project INCA 600398. The calculations were performed using supercomputer resources provided by the Swedish National Infrastructure for Computing (SNIC) at the National Supercomputer Centre (NSC) and Center for Parallel Computing (PDC).2016-06-172016-06-172016-10-04Bibliographically approved