Electronic structures of La0.7-xCsxCa0.3MnO3 probed by X-ray absorption spectroscopy

We report X-ray absorption near edge structure (XANES) spectra of La0.7-xCsxCa0.3MnO3 (x=0, 0.01, 0.05, 0.1) at the Mn, O K- and Mn L3,2-edges. In a stoichiometric compound, the substitution of Cs for La-site could drive a fraction of Mn ions to 5+ valency state. The experimental XANES spectra at Mn K-edge do not support such a proposal. To account this result, one needs to consider the effect of ionic radius of Cs. It is likely that both ionic radius of Cs and valency of Mn act in opposite directions. The XANES spectra both at O K-, and Mn L3,2-edges exhibit prominent changes due to Cs doping, such observed changes are explained by considering Mn 3d-O 2p hybridization and the crystal field effects of Mn ions