Valence state and X-ray photoelectron 2 p spectra of chromium ions in the La 1– x Sr x CrO 3 ( x = 0, 0.1, 0.3, 0.5) system

Room-temperature Cr2 p X-ray photoelectron spectra of samples of the La 1– x Sr x CrO 3 system with x = 0, 0.1, 0.3, and 0.5 are obtained. The profiles of these spectra vary considerably with x . XPS analysis shows that the chromium ions are in a mixed valence state. The introduction of Sr 2+ ions into the lattice is compensated for by the mechanism of Cr 3+ , Cr 4+ , Cr 5+ , and Cr 6+ ion formation. Decomposition of Cr2 p 3/2 spectra into components with profiles corresponding to Cr 3+ , Cr 4+ , Cr 5+ , and Cr 6+ ions has shown that the contribution from Cr6+ ions grows along with with x in the Cr2 p 3/2 spectra, while the contribution from Cr 3+ , Cr 4+ , and Cr 5+ ions is reduced at higher x values.