Synchrotron and Free electron laser Radiation: generation and application (SFR-2016)

XANES investigation of the chromium dichalcogenides CuCr_1-xM’S₂ and MCrX₂

5 Jul 2016, 15:00

1h

2nd and 3rd floors (Budker INP)

Board: 012

Poster X-ray spectroscopy Poster Session

Speaker

Mr Evgeniy Korotaev (Nikolaev Institute of Inorganic Chemistry of the Siberian Branch of the Russian Academy of Sciences)

Description

The chromium dichalcogenides MCrX₂ (M = Cu, Ag, Na, X = O, S, Se) are promising materials for modern electronics. These materials have the potential properties for practical usage : ionic conductivity [1], thermoelectric properties [2], magnetic arrangement[3-4], colossal magnetoresistance, phase metal-insulator transition [4].

There are several different ways of purposeful control of electric and magnetic properties of the chromium dichalcogenides MCrX2: cationic substitution of the chromium atoms with vanadium, iron or manganese atoms (CuCr_1-xM'_xS₂, M' = V, Fe, Mn), co-intercalation of different kinds of atoms into the van-der-waals gap (for example silver in the Cu_1-xAg_xCrS₂), changing type of the chalcogen (CuCrX₂, X = S, Se, Te).

Synthesis of functional materials based on MCrX₂ with necessary properties requires distribution control of atoms on the crystallographic positions in the crystal lattice. This parameter essentially depends on technology of synthesis. In this regard, it is appropriate to use physical methods sensitive to the character of the local environment of atoms in synthesized samples. The XANES-spectroscopy can be used as such method (XANES - X-ray Near Edge Structure).

In the present study a complex experimental and theoretical investigation of the XANES-structures of X-ray absorption K-edges of intercalated MCrX₂ (M = Cu, Ag, X = O, S, Se) and cation-substituted dichalcogenides CuCr_1-xM'_xS₂, (M' = V, Fe, x = 0-0.40) have been carried out. Based on these data the influence of cation substitution of chromium atoms and the influence of types of the chalcogens and the intercalates to the near fine structure of X-ray absorption spectra of the elements in the dichalcogenides CuCr_1-xV_xS₂ and MCrX₂ (M = Cu, Ag, X = O, S, Se) have been investigated.

The reported investigation was funded by RFBR according to the research project No. 16-32-00612.

[1] Almukhametov R.F., Yakshibaev R.A., Gabitov E.V. et al. // Phys. Stat. Sol. (b). – 2003. – 236, N 1. – P. 29 – 33.

[2] Srivastana D., Tewari G.C., Kappinen M., Nieminen R.M. // J. Phys.: Condens.Matter. – 2013. – 25, N. 3 – P. 105504.

[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.