Atomic-Scale Visualization of Polarization Pinning and Relaxation at Coherent BiFeO3/LaAlO3 Interfaces
Atomic-Scale Visualization of Polarization Pinning and Relaxation at Coherent BiFeO3/LaAlO3 Interfaces
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DOI：
10.1002/adfm.201301470
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发表时间：
2014-02-01
影响因子：
19
通讯作者：
Chu, Ying-Hao
中科院分区：
文献类型：
--
作者：
Huang, Rong;Ding, Hang-Chen;Chu, Ying-Hao
复杂的氧化物异质界面具有令人难以置信的各种界面物理现象，目前在向系统引入新功能方面引起了极大的兴趣。在这里，通过在球差（Cs）校正扫描透射电子显微镜（STEM）中结合使用高角度环形暗场（HAADF）成像和环形明场（ABF）成像以及第一性原理计算，研究了相干超四方 BiFeO3/LaAlO3 和菱形 BiFeO3/LaAlO3 异质界面。原子分辨率揭示了两个界面上发生的复杂的铁电极化钉扎和弛豫，BiFeO3 的结构发生了巨大的变化，从立方体变为类超四方体。这些结果能够详细解释非体相结构如何在这种材料的薄膜中稳定。
Complex oxide heterointerfaces, which play host to an incredible variety of interface physical phenomena, are of great current interest in introducing new functionalities to systems. Here, coherent super-tetragonal BiFeO3/LaAlO3 and rhombohedral BiFeO3/LaAlO3 heterointerfaces are investigated by using a combination of high-angle annular dark-field (HAADF) imaging and annular bright-field (ABF) imaging in a spherical aberration (Cs) corrected scanning transmission electron microscope (STEM), and first-principles calculations. The complicated ferroelectric polarization pinning and relaxation that occurs at both interfaces is revealed with atomic resolution, with a dramatic change in structure of BiFeO3, from cubic to super-tetragonal-like. The results enable a detailed explanation to be given of how non-bulk phase structures are stabilized in thin films of this material.