Analysis of Charge Compensation Mechanisms in Pr(1-x)A(x)CoO(3-delta) (A = Ca, Sr) by X-ray Absorption Near-Edge Structure

作者：Yoshioka Tsuyoshi^*; Yamamoto Tomoyuki; Kitada Akihiko

来源：Japanese Journal of Applied Physics, 2012, 51(7): 073201.

DOI：10.1143/JJAP.51.073201

The charge compensation mechanisms in polycrystalline Pr1-xCaxCoO3-delta and Pr1-xCaxCoO3-delta here synthesized by the solid-state reaction method have been investigated by analyzing the Pr-L-3 and Co-K X-ray absorption near-edge structure (XANES) with the aid of first-principles calculations. The valence states of Pr ions in these materials were determined to be trivalent (Pr3+) and independent of the concentration of alkaline-earth ions observed in the Pr-L-3 XANES profile. The Co-K XANES spectra shifted to the higher-energy side with an increase in alkaline-earth concentration and were examined in detail by first-principles calculations. Using calculated XANES results, we successfully determined that the valence state of Co ions is an intermediate value between 3+ and 4+ and increases with an increase in the concentration of alkaline-earth ions in Pr1-xCaxCoO3-delta (A = Ca, Sr) accompanying oxygen vacancy.

• 出版日期2012-7