Mn K-Edge X-Ray Absorption Spectroscopy (XAS) Studies of La1-xSrxMnO3

Abstract

ABSTRACTSystematic Mn K-edge x-ray absorption spectroscopy (XAS) measurements on samples of La1-xSrxMnO3, which are precursors to colossal magnetoresistive (CMR) materials, are reported. Detailed results on the edge or chemical shift as a function of Sr concentration (hole doping) and sample preparation (air vs oxygen annealed), are discussed. For comparison, a systematic XANES study of the Mn K-edge energy shift, denoting valence change in Mn, has been made in standard manganese oxide systems. Contrary to expectations, the variation in near-edge energies for Mn in La0.725Sr0.275MnO3 were small when compared to the difference between that for manganese oxide standards of nominal valence of +3 and +4 (Mn2O3 and MnO2).