X-ray absorption spectroscopy

We report O K-, Ca Kand L3,2-, and Ti L3,2-edge X-ray absorption near edge structure (XANES) spectra of Ba1 xCaxTiO3 (x 1⁄4 0; 0.01, 0.08, and 1) and the electronic properties inferred from these XANES spectra. The spectra of O K-, Ca L3,2and Ti L3,2-edges show characteristic spectral features attributable to the t2g and eg bands. The Ti and Ca L3,2-edge spectra contain two sets of L3 and L2 features with a L3–L2 separation of about 5.5 and 3.4 eV, respectively. We also observe a pre-edge feature in the Ca Kedge spectra and drastically reduced t2g features in the Ca L3,2-edge spectra. Our XANES spectra reveal that the Ca 3d bands are low-lying and the Ca 3d t2g bands are partially occupied. r 2004 Elsevier Inc. All rights reserved. PACS: 78.70.Dm; 71.20. b; 77.84. s