COMPOSITIONAL DEPENDENCE OF X-RAY ABSORPTION SPECTRA ON MAGNETIC CIRCULAR DICHROISM AND NEAR-EDGE STRUCTURE AT CO K EDGE IN La1-xSrxCoO3 (0= x= 0.6)

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 43, no. 7A, pp. 4171-4178. 2004 Vol. 43; no. 7A; pp. 4171 - 4178
• Main Authors: Hanashima, T, Azuhata, S, Yamawaki, K, Shimizu, N, Mori, T, Tanaka, M
• Format: Journal Article
• Language: English
• Published: 01.01.2004
• ISSN: 0021-4922

Authors studied the effect of Sr doping on the magnetic structure of La1-xSrxCoO3 (x=0, 0.2, 0.3, 0.4, 0.5 and 0.6) by X-ray magnetic circular dichroism (XMCD) at Co K absorption edges. A negative XMCD peak was clearly observed for pure LaCoO3 at E=7.719 keV within the threshold region of the main edge, suggesting the existence of the intermediate-spin state of Co3+. A positive XMCD peak appeared at E=7.723 keV by Sr substitution of La in LaCoO3 (x= 0.2) in accordance with the low-spin state of Co4+ and XANES spectra. A negative XMCD peak was also observed at the pre-edge, which can be explained as the hybridization with the neighboring Co4+ in the dipole transition. The dispersion-type XMCD signals at the main edge may be rationalized with the hypothetical double-exchange interaction between Co3+ and Co4+. 45 refs.