Electronic relaxation effects on x-ray spectra of titanium and transition-metal carbides and nitrides

High-resolution titanium K x-ray absorption spectra from pure metal, carbide, and nitride are measured using synchrotron radiation. It is shown that the local partial density of states at the metal site is adequate to describe the near-edge features observed. The magnitude of the electron screening to a suddenly switched-on core-hole potential is investigated and found to be correlated to the density of occupied electron states at the Fermi surface. The dynamical aspects of the screening process show up in the extended x-ray absorption fine-structure region of the spectra and influence the phase and amplitude of the photoelectron wave function. Several structural properties of these compounds are also considered.