2:1 Charge disproportionation in perovskite-structure oxide La1/3Ca2/3FeO3 with unusually-high-valence Fe3.67+
2:1 Charge disproportionation in perovskite-structure oxide La1/3Ca2/3FeO3 with unusually-high-valence Fe3.67+
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钙钛矿结构氧化物 La1/3Ca2/3FeO3 与异常高价 Fe3.67 的 2:1 电荷歧化
DOI：
10.1016/j.jssc.2016.11.027
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
and Y. Shimakawa
中科院分区：
文献类型：
--
作者：
H. Guo;Y. Hosaka;H. Seki;T. Saito;N. Ichikawa;and Y. Shimakawa
在高温高压条件下合成了具有高价态Fe3.67+的La_（1/3）Ca_（2/3）FeO_3。该化合物的晶体结构为α 2a ×2a× α 2a的多孔晶胞，其中A位的La和Ca离子是无序的。在217 K时，Fe 3.67+以2：1的比例与Fe 3+和Fe 5+发生电荷交换，这种交换伴随着磁性和输运性质的转变。电荷分离的Fe 3+和Fe 5+沿<111>立方钙钛矿电池的方向沿着排列。Fe在La_（1/3）Ca_（2/3）FeO_3中的局域电磁环境与Fe在La_（1/3）Sr_（2/3）FeO_3中的局域电磁环境十分相似，Fe ~（3+）和Fe ~（5+）的2：1电荷交换模式也与La_（1/3）Sr_（2/3）FeO_3中的相同。
La1/3Ca2/3FeO3with unusually-high-valence Fe3.67+was synthesized at a high pressure and high temperature. The compound crystallizes in a √2a×2a×√2aperovskite cell in which the La and Ca ions at the A site are disordered. At 217 K the Fe3.67+shows charge disproportionation to Fe3+and Fe5+in a ratio of 2:1, and this disproportionation is accompanied by transitions in magnetic and transport properties. The charge-disproportionated Fe3+and Fe5+are arranged along the <111> direction of the cubic perovskite cell. The local electronic and magnetic environments of Fe in La1/3Ca2/3FeO3are quite similar to those of Fe in La1/3Sr2/3FeO3, and the 2:1 charge disproportionation pattern of Fe3+and Fe5+in La1/3Ca2/3FeO3is also the same as that in La1/3Sr2/3FeO3.