A theoretical study of disorder in transition metal aluminides: Vacancies and antistructure atoms

Korringa-Kohn-Rostoker-Coherent-Potential-Approximation (KKR-CPA) calculations were performed on FeAl and NiAl in the CsCl structure with various concentrations of vacancies on the transition metal sublattice and antistructure atoms on both sublattices. It is found that transition metal vacancies only bring about minor changes in the density of states, whereas Fe atoms on the Al sublattice give rise to additional states near the Fermi energy. X-ray photoelectron spectra were calculated and-in the case of NiAl-compared with experiment.