Anomalous phase diagram of ferroelectric (Ba,Ca)TiO3 single crystals with giant electromechanical response.
Anomalous phase diagram of ferroelectric (Ba,Ca)TiO3 single crystals with giant electromechanical response.
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DOI：
10.1103/physrevlett.100.227601
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发表时间：
2008-06
影响因子：
8.6
通讯作者：
D. Fu;M. Itoh;S. Koshihara;Taichi Kosugi;S. Tsuneyuki
中科院分区：
文献类型：
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作者：
D. Fu;M. Itoh;S. Koshihara;Taichi Kosugi;S. Tsuneyuki
我们报道了铁电单晶 Ba1-xCaxTiO3 (0.02<x<0.34) 的反常相演化，并证明了量子涨落对铁电相变的显着影响。此外，还证明了此类晶体的大机电响应。我们的结果表明，控制钙钛矿氧化物铁电性的有效方法不仅可以通过A位原子与氧之间的共价键来实现，还可以通过用具有偏心性质的小离子取代A位来实现。理论计算支持这样的观点：Ba 位点中较小 Ca 离子的偏心位移在 Ba1-xCaxTiO3 的奇异性质中发挥着重要作用。
We report the anomalous phase evolution in ferroelectric single crystals Ba1-xCaxTiO3 (0.02<x<0.34), and demonstrate the significant effects of quantum fluctuation on the ferroelectric phase transition. In addition, large electromechanical responses in this class of crystals are also demonstrated. Our results indicate that an effective approach to control the ferroelectricity of perovskite oxide can be realized not only by the covalency between A site atom and oxygen but also by the substitution of A site with small ions with off-centering nature. Theoretical calculations support the idea that the off-center displacements of the smaller Ca ions in the Ba-site play an important role in the exotic natures of Ba1-xCaxTiO3.