Charge-orbital ordering and verwey transition in magnetite
Charge-orbital ordering and verwey transition in magnetite
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DOI：
10.1103/physrevlett.93.156403
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发表时间：
2004-10-08
影响因子：
8.6
通讯作者：
Huang, DJ
中科院分区：
文献类型：
--
作者：
Jeng, HT;Guo, GY;Huang, DJ
局域密度近似+Hubbard U （LDA+U）能带结构计算表明，Fe3O4在Verwey转变温度以下形成绝缘电荷轨道有序态。计算的电荷顺序与最近的实验结果吻合较好。我们在八面体Fe2+亚晶格上发现了一个相关的t（2g）轨道顺序。这种轨道排序主要是由现场库仑相互作用产生的。这一发现揭示了有关维维跃迁的基本问题，如电荷有序和绝缘间隙形成的机制，以及电荷有序的安德森准则的不服从。
Local density approximation+Hubbard U (LDA+U) band structure calculations reveal that magnetite (Fe3O4) forms an insulating charge-orbital-ordered state below the Verwey transition temperature. The calculated charge ordering is in good agreement with that inferred from recent experiments. We found an associated t(2g) orbital ordering on the octahedral Fe2+ sublattice. Such an orbital ordering results primarily from the on-site Coulomb interaction. This finding unravels such fundamental issues about the Verwey transition as the mechanism for the charge ordering and for the formation of the insulating gap, as well as the nonobedience of the Anderson's criterion for the charge ordering.