X-ray absorption near-edge spectroscopy study of Mn and Co valence states in LaMn1-xCoxO3 (x=0-1)

A systematic study of the valence states of Mn and Co in the perovskite series LaMn1-xCoxO3 (x=0 to 1) by means of x-ray absorption near edge spectroscopy (XANES) at the K-edges is presented. The chemical shift and the evolution of the pre-edge features reveal a gradual increase of the average oxidation level of both, Mn and Co ions, with Co doping, which suggests that mixed valence states of Co2+/Co3+ and Mn3+/Mn4+ exist in the whole solid solution range. The relation of the results to the magnetic properties of the compounds is discussed.