Structural study of CuCr1 − xVxS2 substitutional solid solutions

• Published in: Surface investigation, x-ray, synchrotron and neutron techniques x-ray, synchrotron and neutron techniques, 2010, Vol.4 (4), p.640-644
• Main Authors: Vasil’eva, I. G., Kriventsov, V. V.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Materials Science; Surfaces and Interfaces; Thin Films
• ISSN: 1027-4510; 1819-7094
• DOI: 10.1134/S1027451010040178

The local structure and charged state of metal atoms in the CuCrS 2 matrix and CuCr 1 − x V x S 2 solid solutions of substitution of vanadium for chromium (0 < x < 0.25) are studied by x-ray absorption spectroscopy (XAFS) using synchrotron radiation. According to XANES spectra (near-edge fine structures), introducing vanadium does not change the charged state of matrix elements and they exist as Cu(1+), Cr(3+), V(3+), and S(2−) in the solid solution. According to EXAFS spectra (extended fine structures), introducing vanadium slightly distorts the local structures of both Cr and Cu atoms (to a greater extent for copper than for chromium). The XAFS analysis data show that vanadium only partially filled vacant positions (specified by the composition of the initial mixture) in the chromium sublattice, the majority of them being located in irregular positions of slightly distorted octahedrons consisting of sulphur atoms. It is shown that the substitution effect leads to deformation (compression) of the lattices of CuCr 1 − x V x S 2 samples without changing their crystallochemical structures and symmetries, but changes their magnetic structures.