Electronic structure of Co_xTiSe₂ and Cr_xTiSe₂

The results of investigations of intercalated compounds Cr_xTiSe₂ and Co_xTiSe₂ by x-ray photoelectron spectroscopy and x-ray emission spectroscopy are presented. The data obtained are compared with theoretical results of spin-polarized band-structure calculations. A good agreement between theoretical and experimental data for the electronic structure of the investigated materials has been observed. The interplay between the M 3d–Ti 3d hybridization (M=Cr, Co) and the magnetic moment at the M site is discussed. A 0.9-eV large splitting of the core Cr 2p_3/2 level was observed, which reveals a strong exchange magnetic interaction of 3d-2p electrons of Cr. In the case of a strong localization of the Cr 3d electrons (for x<0.25), the broadening of the Cr L spectra into the region of the states above the nominal Fermi level was observed and attributed to x-ray reemission. The measured kinetic properties are in good accordance with spectral investigations and band calculation results.