Universal Behavior and Electric-Field-Induced Structural Transition in Rare-Earth-Substituted BiFeO3
Universal Behavior and Electric-Field-Induced Structural Transition in Rare-Earth-Substituted BiFeO3
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DOI：
10.1002/adfm.200902017
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发表时间：
2010-04-09
影响因子：
19
通讯作者：
Takeuchi, Ichiro
中科院分区：
文献类型：
--
作者：
Kan, Daisuke;Palova, Lucia;Takeuchi, Ichiro
报道了稀土掺杂钙钛矿型BiFeO_3的普遍行为。发现从铁电菱面体相到正交相的结构转变表现出双极化滞后回线和显著增强的机电性能，独立于RE掺杂剂种类而发生。通过控制A位阳离子的平均离子半径，可以普遍地实现结构转变。使用基于第一性原理的计算，探索BiFeO3的能量景观，并提出双磁滞回线和伴随的压电系数增强的起源是电场诱导的从顺电正交相到极性菱形相的转变。
The discovery of a universal behavior in rare-earth (RE)-substituted perovskite BiFeO3 is reported. The structural transition from the ferroelectric rhombohedral phase to an orthorhombic phase exhibiting a double-polarization hysteresis loop and substantially enhanced electromechanical properties is found to occur independent of the RE dopant species. The structural transition can be universally achieved by controlling the average ionic radius of the A-site cation. Using calculations based on first principles, the energy landscape of BiFeO3 is explored, and it is proposed that the origin of the double hysteresis loop and the concomitant enhancement in the piezoelectric coefficient is an electric-field-induced transformation from a paraelectric orthorhombic phase to the polar rhombohedral phase.