Electronic structures of SrMn(1-x)Mo(x)O(3) (0 <= x <= 0.75) perovskite oxides investigated by XAS and PES

Abstract

Electronic structures of perovskite oxides of SrMn1-xMoxO3 (0 <= x <= 0.75) have been investigated by employing soft x-ray absorption spectroscopy (XAS) and photoemission spectroscopy (PES). It is found that the valence states of Mn ions change systematically from Mn4+ for x = 0, to nearly Mn3+ for x = 0.3, and Mn2+ for x = 0.5, and then remain as Mn2+ for x >= 0.5. Both the Mo 3d core-level PES and Mo 3p XAS spectra show that the valence states of Mo ions remain unchanged as being hexavalent (Mo6+) for x <= 0.5 but that they decrease for x > 0.5 with increasing x. This study shows that Mo ions are mixed-valent for x > 0.5 in SrMn1-xMoxO3, either with the Mo4+-Mo6+ configuration or with the Mo4+-Mo5+-Mo6+ configuration. (C) 2011 American Institute of Physics. [doi. 10.1063/1.3560890]