Photoemission spectroscopy study of metal-insulator transition in SrMn1-x Fex O3

Abstract

Electronic structures of cubic perovskite oxides of SrMn1-xFexO3(0 <= x <= 1) have been investigated by employing photoemission spectroscopy (PES) and soft x-ray absorption spectroscopy (XAS). The spectral intensity near the Fermi level [I(E-F)] is found to be finite in Fe 3d PES of SrFeO3. I(E-F) increases with x in Fe 3d PES of SrMn1-xFexO3, while it is negligibly small in Mn 3d PES for all x. The O 1s XAS for SrFeO3 also shows the finite spectral intensity near the Fermi level. These findings provide the experimental evidence for the metal-insulator transition in SrMn1-xFexO3 with decreasing x and imply the importance of Fe 3d electrons in determining the metallic states in SrMn1-xFexO3. First principles band structure calculations for SrFeO3 and SrMnO3 support these findings in PES/XAS.