The valence states of the Mn ions in Pr 1-xA xMnO 3-δ (A = Ca, Sr) are investigated by Mn-L 3 X-ray absorption near-edge structure (XANES) analysis. The spectral fine structures in the Mn-L 3 XANES analysis show a significant difference between Pr 0.5Ca 0.5MnO 3-δ and Pr 0.5Sr 0.5MnO 3-δ, a paramagnetic insulator and a ferromagnetic metal, respectively, at room temperature, whereas the spectral structures of Pr 0.7Ca 0.3MnO 3-δ and Pr 0.7Sr 0.3MnO 3-δ, paramagnetic insulators, are almost identical. These results indicate that the valence states of the Mn ions in these materials are highly correlated with their magnetic and electrical properties. A significant difference was also found between the Mn-L 3 XANES profiles of Pr 1-xCa xMnO 3-δ and the profiles formed by the linear combination of the Mn-L 3 XANES spectra of PrMnO 3 (Mn 3+) and CaMnO 3 (Mn 4+). This difference indicates that the Mn ions in these materials do not have a mixed-valence state of 3+ and 4+, but have an intermediate valence state o 3+ and 4+.
|ジャーナル||Journal of Electron Spectroscopy and Related Phenomena|
|出版ステータス||Published - 2012 8月 1|
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