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The solid solution based on the copper chromium disulfide CuCrS2 are promising functional materials for modern electronics applications. These compounds exhibit the potential properties for practical usage: the thermoelectric properties [1], the ionic conductivity [2], the helimagnetic arrangement [3-4], the colossal magnetoresistance and the phase metal-insulator transition [4].
There are several approaches to control the electric and magnetic properties of CuCrS2-based compounds: the cationic substitution of chromium atoms with transition metal atoms (CuCr1-xMxS2, M = V, Fe, Mn), the co-intercalation of the Van der Waals gap with two atom types (Cu1-xAgxCrS2) and the chalcogen substitution (CuCrS2, X = S, Se, Te). It was shown that the low dopant solid solutions CuCr1-xMxS2 exhibit promising thermoelectric properties. The key aspect to control the electrophysical properties of thermoelectric materials is the understanding of the electronic structure features. The corresponding data could be obtained from both the quantum-chemical calculations and the experimental techniques sensitive to the electronic structure. In this regard, the study of the X-ray absorption edges near edge structure (XANES) features could provide useful information about the conduction band structure. Thus, this study involves a purposeful synthesis of the lanthanide doped solid solutions CuCr0.99Ln0.01S2 (Ln=La, Ce, Gd) and detailed study of their electronic and band structure. A comprehensive experimental and theoretical study of the X-ray absorption edges of the matrix elements and doped-lanthanide atoms in the cation-substituted disulfides CuCr0.99Ln0.01S2 was carried out. Based on the obtained results, the cationic substitution with lanthanide atoms affect to the conduction band structure was studied.
The study was carried out with a funding from the Russian Science Foundation (project No. 19-73-10073). The software program design for the experimental XANES spectra shape correction was supported by RFBR grant №16-32-00612.
[1] Korotaev E.V, Syrokvashin M.M., I.Yu. Filatova, et al. // J. Electron. Mater. -2018.-47. –p. 3392-3397.
[2] Akmanova G.R., Davleshina A.D., // Lett.Mater.-2013.- 3. –p.76-78.
[3] Karmakar A., Dey K., Chatterjee S. et al. // Appl. Phys. Letters. – 2014. –104, N. 5. – P. 052906.
[4] Abramova G.M., Petrakovskii G.A. // Low Temperature Physics. – 2006. – 32, N. 8/9. – p. 954-967.
