Quadrupole splitting and ground state in FeS and NiS (Fe57)

Abstract

The electronic structures of lanthanum chromites, pure and doped with magnesium and strontium, have been studied in comparison with Cr2O3 and La2O3 through the use of X-ray photo-electron spectroscopy. The main peaks and satellites of inner and outer electrons are properly assigned. The band structure of LaCrO3 is determined by using the XPS data and a calculation based on point charge model. The partially filled Cr(3d) band is localized. The conduction is mainly extrinsic. The measured Fermi-level is close to the valence band indicating a low activation energy in agreement with the results of conductivity measurements.