X-ray photoelectron spectra of perovskite-type cobalt oxides La1-xSrxCoO3-y (x = 0.4, 0.6)

Abstract

X-ray photoelectron spectra have been collected for bulk samples of the ternary perovskite-type cobalt oxides La1−xSrxCoO3−y (x=0.4, 0.6). Anomalously low binding energy components for the O 1s and Sr 3d photopeaks, similar to those recorded for the family of high temperature superconducting copper oxides, have been observed. These observations have been interpreted in terms of an initial-state screening mechanism and the implications for the electronic structure of “metallic” oxides are discussed. The Co 2p signature is typical of low spin Co3+, suggesting that doping by strontium leads to the formation of holes in the oxygen bands.