Iron-resonant valence band photoemission and oxygen near edge x-ray absorption fine structure study on La1−xSrxFe0.75Ni0.25O3−δ

Abstract

Iron resonant valence band photoemission spectra (VB PES) of Sr substituted LaFe0.75Ni0.25O3−δ have been recorded across the Fe 2p-3d absorption threshold to obtain Fe specific spectral information on the 3d projected partial density of states. Comparison with La1−xSrxFeO3 resonant VB PES literature data suggests that substitution of Fe by Ni forms electron holes which have mainly O 2p character. Substitution of La by Sr increases the hole concentration to an extent that the eg structure vanishes. The variation in the eg and t2g structures is paralleled by the changes in the electrical conductivity.