Co K-edge X-ray absorption near-edge spectra at 300 K and magnetic studies for the rhombohedral LaCoO3 with low-spin state to intermediate-spin (IS) state transition Ts≃105 K and orthorhombic EuCoO 3 (Ts≃295 K) are reported. The small pre-edge feature observed is from 1s-3d dipole transition, which is weakly allowed through the hybridization of Co 4p states with 3d states of neighboring Co atoms. For both samples in the IS state, pre-edge can be fitted using three peaks with energy separation P2 - P1 = 2.0 eV for R = La and Eu, and P3 - P2 = 1.5 eV for R = La and 1.3 eV for R = Eu. Since the thermally excited IS state is a mixed t2g 5eg1 and d7L (t2g 6eg1 or t2g5e g2), with almost filled t2g↑ states. From reported band structure calculation, the three peaks P1, P 2, P3 are probably corresponding to the unfilled t 2g↓, eg↑ and eg↓ states, respectively.
- Spin-state transition
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering