Mn K-edge X-ray absorption spectroscopy (XAS) studies of La{sub 1{minus}x}Sr{sub x}MnO{sub 3}

Systematic Mn K-edge x-ray absorption spectroscopy (XAS) measurements on samples of La{sub 1{minus}x}Sr{sub x}MnO{sub 3}, 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 La{sub 0.725}Sr{sub 0.275}MnO{sub 3} were small when compared to the difference between that for manganese oxide standards of nominal valence of +3 and +4 (Mn{sub 2}O{sub 3} and MnO{sub 2}).