| Autor: |
Korotaev, E. V., Syrokvashin, M. M., Filatova, I. Yu., Kriventsov, V. V. |
| Zdroj: |
Journal of Surface Investigation: X-Ray, Synchrotron & Neutron Techniques; Dec2023, Vol. 17 Issue 6, p1472-1482, 11p |
| Abstrakt: |
The comprehensive experimental and theoretical study of the structure of the valence band and conduction band of vanadium-substituted solid solutions CuCr1 – xVxS2 (x = 0–0.40) is carried out using both quantum chemistry calculations and X-ray absorption and emission spectroscopy. For a detailed analysis of the fine structure of the X-ray emission and absorption spectra, the experimental spectra are corrected for the width of the instrument-distortion function and the width of the internal level. The corrected experimental spectra are compared with the distributions of the partial atomic densities of states of metals and sulfur obtained from quantum-chemical calculations within the framework of density functional theory using the BAND and FDMNES software packages. Comparison of the experimental and theoretical data allows one to interpret changes in the fine structure of the X-ray absorption K-edges and X-ray emission lines of the valence band with an increase in the vanadium concentration. It is shown that after cationic substitution the character of the distribution of occupied and unoccupied states for copper, chromium, and sulfur is similar to that for the initial copper–chromium disulfide. The contribution of vanadium states replaces the contribution of chromium states at the valence-band top and the conduction-band bottom, which causes the metal–insulator transition. Interpretation of the nonmonotonic character of the temperature dependence of the Seebeck coefficient of CuCr1 – xVxS2 solid solutions, obtained for the first time, is carried out using the results of the experimental and theoretical study of the electronic structure. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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