First-Principles Predictions of Giant Electric Polarization
First-Principles Predictions of Giant Electric Polarization
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DOI：
10.1143/jjap.44.7130
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发表时间：
2005-09
影响因子：
1.5
通讯作者：
Yoshitaka Uratani;T. Shishidou;F. Ishii;T. Oguchi
中科院分区：
文献类型：
--
作者：
Yoshitaka Uratani;T. Shishidou;F. Ishii;T. Oguchi
基于第一性原理Berry相方法，预测PbVO 3和BiCoO 3的巨电极化大于150 µC/cm 2。稳定的晶体结构是四边形扭曲与一个大的c/a比和显着的离子位移打破中心对称性。在PbVO 3中，稳定这种高度扭曲的结构并实现绝缘电子结构，导致巨极化的关键因素是V4+ d1构型中铁轨道和反铁自旋有序的共存。结果表明，同样的电子机制也适用于BiCoO 3与Co 3 + d 6配置。
Giant electric polarization of more than 150 µC/cm2 is predicted for PbVO3 and BiCoO3 on the basis of the first-principles Berry-phase method. The stable crystal structure is tetragonally distorted with a large c/a ratio and significant ionic displacements breaking centrosymmetry. In PbVO3, the key factor that stabilizes such a highly distorted structure and realizes an insulating electronic structure, leading to giant polarization, is the coexistence of ferro-orbital and antiferro-spin orderings in the V4+ d1 configuration. It is shown that the same electronic mechanism works also for BiCoO3 with Co3+ d6 configuration.