Electronic structure of X2ZrSn- and XZrSn-type Heusler alloys with X = Co or Ni

X-ray photoemission spectroscopy (XPS) measurements have been performed on the intermetallic compounds Ni2ZrSn, NixZr1-xSn, Co2ZrSn, and CoxZr1-xSn. The XPS valence bands show a small density of states at the Fermi level, and the position of Co and Ni d states below this energy. The core level XPS spectra are shifted in comparison with the respective spectra of the pure elements suggesting a redistribution of charge between atoms. XPS valence bands have been compared with total density of states distribution curves by the use of spin-polarized linear muffin-tin orbital calculations.