Polarized x-ray-absorption spectra of TiS2, TiSe2, and TiTe2

We studied the anisotropy of the unoccupied electron states of three titanium dichalcogenides by means of polarized x-ray-absorption spectroscopy. The experimental spectra of TiS2, TiSe2, and TiTe2 at the Ti K edge and of TiTe2 at the Te L-1 edge were compared with the results of real-space multiple-scattering calculations. The local angular momentum projections of the densities of states at the titanium sites are presented for energies up to 25 eV above the Fermi level. The Ti K,edge spectra of all three dichalcogenides are quite similar to each other provided the differences in their lattice constants are suppressed by comparing the spectra in equivalent energy scales. However, the correspondence between the Te L-1 edge of TiTe2 and the S K edge of TiS2 is much less pronounced. For most of the spectra good agreement between experiment and theory was found. [S0163-1829(98)01336-8].