Determination of valence state of Mn ions in Pr(1-x)A(x)MnO(3-delta) (A = Ca, Sr) by Mn-L-3 X-ray absorption near-edge structure analysis

作者：Kanamori Haruto; Yoshioka Tsuyoshi; Hirose Kazuyuki; Yamamoto Tomoyuki^*

来源：Journal of Electron Spectroscopy and Related Phenomena, 2012, 185(5-7): 129-132.

DOI：10.1016/j.elspec.2012.03.003

• Perovskite manganite
• X-ray absorption spectrum
• Valence state
• Magnetic property
• Electrical conductivity

The valence states of the Mn ions in Pr(1-x)A(x)MnO(3-delta) (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 Pr0.5Ca0.5MnO3-delta and Pr0.5Sr0.5MnO3-delta, a paramagnetic insulator and a ferromagnetic metal, respectively, at room temperature, whereas the spectral structures of Pr0.7Ca0.3MnO3-delta and Pr0.7Sr0.3MnO3-delta, 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 Pr1-xCaxMnO3-delta and the profiles formed by the linear combination of the Mn-L-3 XANES spectra of PrMnO3 (Mn3+) and CaMnO3 (Mn4+). 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+.

• 出版日期2012-8