We report the soft–X-ray absorption spectra at the oxygen K-edge of La1 – xSrxCoO3 – δ(x = 0.0, 0.1, 02, 0.3 and 0.4) series with experimentally determined δ values. We show that the doping of holes by replacing La3+with Sr2+induces states within the band gap of the insulating undoped compound for small x and these doped states have a very substantial oxygen 2p character. This indicates that the insulating compounds belong to the charge transfer insulator regime. With increasing Sr content, the doped states broaden into a band overlapping the top of the primarily oxygen p-derived band, leading to an insulator-metal transition at x ³ 0.2.
All Science Journal Classification (ASJC) codes
- 物理與天文學 (全部)