X-ray photoelectron spectra and electronic energy structure of tetragonal CuxNi1-xTi alloys

The electronic energy structure (EES) of Cu0.8Ni0.2Ti and Cu0.6Ni0.4Ti alloys, stoichiometric CuTi compound with a tetrahedral CuTi-type crystal lattice, and cubic NiTi was studied experimentally and theoretically. The experimental study of valence band EES was carried out by X-ray photoelectron spectroscopy (XPS). The EES of both the stoichiometric compounds and the alloys was calculated using the cluster version of multiple scattering theory in a self-consistent field approximation. The calculation and experimental results are in good agreement. The major contribution to XPS of the studied compounds is from the d states of copper and nickel. The specifics of chemical bonding in the compounds are discussed. The EES of tetragonal Cu-Ni-Ti alloys is modeled.