X-RAY PHOTOELECTRON SPECTROSCOPIC STUDIES OF THE CHARGED STATE OF 3<i>d</i> METAL IONS IN CuCr<sub>1-<i>x</i></sub>V<sub><i>x</i></sub>S<sub>2</sub> (<i>x</i> = 0-0.4)
The charged state of the 3d metal ions in layered cation-substituted disulfides CuCr1-xVxS2 was studied by X-ray photoelectron spectroscopy. An analysis of the energy positions and structure of the Cu2p3/2 and Cr2p3/2 X-ray photoelectron lines showed that the corresponding polycrystalline samples of CuCr1-xVxS2 contained mixed-valence chromium and copper ions. It was shown that the charged states of chromium and copper ions depended on the concentration of vanadium cations (x). The presence of mixed-valence Cu1+ and Cu2+ ions in CuCr1-xVxS2 may be correlated with the crystal structure of the corresponding layered disulfides.