BiFeO3 domain wall energies and structures: a combined experimental and density functional theory+U study.
BiFeO3 domain wall energies and structures: a combined experimental and density functional theory+U study.
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DOI：
10.1103/physrevlett.110.267601
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发表时间：
2013-06
影响因子：
8.6
通讯作者：
Yi Wang;C. Nelson;A. Melville;B. Winchester;S. Shang;Zi-kui Liu;D. Schlom;Xiaoqing Pan;Long-qing Chen
中科院分区：
文献类型：
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作者：
Yi Wang;C. Nelson;A. Melville;B. Winchester;S. Shang;Zi-kui Liu;D. Schlom;Xiaoqing Pan;Long-qing Chen
结合密度泛函理论+U计算和像差校正的透射电子显微镜图像，我们确定了BiFeO3中109°，180°和71°畴壁的原子结构和能量。我们发现一个实质性的Bi亚晶格位移和一个相当均匀的Fe亚晶格的墙壁。对于109°、180°和71°壁，计算的壁能（γ）遵循γ109<γ180<γ71的顺序。我们将高的71°壁能归因于氧八面体的相反倾斜旋转，而将低的109°壁能归因于氧八面体穿过畴壁的相反扭转旋转。
We determined the atomic structures and energies of 109°, 180°, and 71° domain walls in BiFeO3, combining density functional theory+U calculations and aberration-corrected transmission electron microscopy images. We find a substantial Bi sublattice shift and a rather uniform Fe sublattice across the walls. The calculated wall energies (γ) follow the sequence γ109<γ180<γ71 for the 109°, 180°, and 71° walls. We attribute the high 71° wall energy to an opposite tilting rotation of the oxygen octahedra and the low 109° wall energy to the opposite twisting rotation of the oxygen octahedra across the domain walls.