General rule for displacive phase transitions in perovskite compounds revisited by first principles calculations.
General rule for displacive phase transitions in perovskite compounds revisited by first principles calculations.
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DOI：
10.1103/physrevlett.94.035502
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发表时间：
2005-01
影响因子：
8.6
通讯作者：
T. Tohei;A. Kuwabara;T. Yamamoto;F. Oba;I. Tanaka
中科院分区：
文献类型：
--
作者：
T. Tohei;A. Kuwabara;T. Yamamoto;F. Oba;I. Tanaka
最近对LaAlO_3的高压实验表明，该化合物是与区界声子有关的位移相变“一般规律”的例外。在本研究中，实验结果成功地证实了第一性原理计算。声子频率的压力依赖性以及相变压力的定量再现。我们发现，该行为不是LaAlO3特有的，而是普遍存在的。RAlO3（R = La、Nd、Sm和Gd）和LaGaO3可以被分类在同一组中。
A recent high pressure experiment on LaAlO3 has revealed that the compound is an exception for the "general rule" of displacive phase transition associated with zone-boundary phonons. In the present study, the experimental result is successfully confirmed by first principles calculations. The pressure dependence of phonon frequencies as well as the phase transition pressure is quantitatively well reproduced. We found that the behavior is not peculiar to LaAlO3 but rather ubiquitous. RAlO3 (R = La, Nd, Sm, and Gd) and LaGaO3 can be classified in the same group.