Ligand-hole localization in oxides with unusual valence Fe.
Ligand-hole localization in oxides with unusual valence Fe.
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DOI：
10.1038/srep00449
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发表时间：
2012
影响因子：
4.6
通讯作者：
Shimakawa, Yuichi
中科院分区：
文献类型：
--
作者：
Chen, Wei-Tin;Saito, Takashi;Hayashi, Naoaki;Takano, Mikio;Shimakawa, Yuichi
铁的不寻常的高价态稳定在几种氧化物中。A位有序钙钛矿结构氧化物中含有这些铁离子，并在低温下表现出不同的电子行为，如CaCu3Fe4O 12中的电荷交换（4Fe 4 + → 2Fe 3 + +2Fe 5+）和LaCu3Fe4O 12中的位间电荷转移（3Cu 2 + +4Fe 3.75 + → 3Cu 3 + +4Fe 3+）。本文报道了CaCu_3Fe_4O_（12）和LaCu_3Fe_4O_（12）固溶体的合成，并解释了它们的不寻常的铁价态的不稳定性是如何得到缓解的。虽然这些行为在简单的离子模型中看起来完全不同，但它们都可以用配体空穴的局域化来解释，这些空穴是由氧化物中铁d和氧p轨道的强杂化产生的。CaCu_3Fe_4O_（12）的电荷分离局域化行为被认为是配体空穴的电荷有序化，LaCu_3Fe_4O_（12）的位间电荷转移局域化行为被认为是配体空穴的Mott跃迁。
Unusual high-valence states of iron are stabilized in a few oxides. A-site-ordered perovskite-structure oxides contain such iron cations and exhibit distinct electronic behaviors at low temperatures, e.g. charge disproportionation (4Fe4+ → 2Fe3+ + 2Fe5+) in CaCu3Fe4O12 and intersite charge transfer (3Cu2+ + 4Fe3.75+ → 3Cu3+ + 4Fe3+) in LaCu3Fe4O12. Here we report the synthesis of solid solutions of CaCu3Fe4O12 and LaCu3Fe4O12 and explain how the instabilities of their unusual valence states of iron are relieved. Although these behaviors look completely different from each other in simple ionic models, they can both be explained by the localization of ligand holes, which are produced by the strong hybridization of iron d and oxygen p orbitals in oxides. The localization behavior in the charge disproportionation of CaCu3Fe4O12 is regarded as charge ordering of the ligand holes, and that in the intersite charge transfer of LaCu3Fe4O12 is regarded as a Mott transition of the ligand holes.
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影响因子：
2.6
作者：
BIANCONI, A;BUDNICK, J;DEMAZEAU, G
通讯作者：
DEMAZEAU, G
影响因子：
3.7
作者：
BOCQUET, AE;FUJIMORI, A;TAKANO, M
通讯作者：
TAKANO, M
影响因子：
1.7
作者：
Kobayashi, W;Terasaki, I;Ando, Y
通讯作者：
Ando, Y
影响因子：
3.3
作者：
TAKANO, M;KAWACHI, J;TAKEDA, Y
通讯作者：
TAKEDA, Y
影响因子：
3.7
作者：
POTZE, RH;SAWATZKY, GA;ABBATE, M
通讯作者：
ABBATE, M