Why Are There So Few Perovskite Ferroelectrics?
Why Are There So Few Perovskite Ferroelectrics?
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DOI：
10.1021/jp402046t
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发表时间：
2013-07-04
影响因子：
3.7
通讯作者：
Fennie, Craig J.
中科院分区：
文献类型：
--
作者：
Benedek, Nicole A.;Fennie, Craig J.
我们使用对称性论证和第一性原理计算相结合的方法来探索钙钛矿族材料中结构扭曲和铁电性之间的联系。我们解释了八面体旋转在抑制这些材料中铁电性方面的作用，并表明，随着容差系数的减小，仅靠旋转不能完全抑制铁电性。我们的结果表明，在这些情况下，起决定作用的是伴随旋转的阳离子位移(“隐藏”在Glazer符号中)，而不是旋转本身。我们利用在这个问题的分析中获得的知识来解释FeTiO_3和ZnSnO_3等R3c材料中铁电性的起源，并为设计和合成新的钙钛矿型铁电材料提出策略。我们的结果不仅对钙钛矿的基本晶体化学有意义，而且对发现新的功能材料也有重要意义。
We use a combination of symmetry arguments and first principles calculations to explore the connection between structural distortions and ferroelectricity in the perovskite family of materials. We explain the role of octahedral rotations in suppressing ferroelectricity in these materials and show that, as the tolerance factor decreases, rotations alone cannot fully suppress ferroelectricity. Our results show that it is cation displacements ("hidden" in Glazer notation) that accompany the rotations, rather than the rotations themselves, that play the decisive role in suppressing ferroelectricity in these cases. We use the knowledge gained in our analysis of this problem to explain the origin of ferroelectricity in R3c materials such as FeTiO3 and ZnSnO3 and to suggest strategies for the design and synthesis of new perovskite ferroelectrics. Our results have implications not only for the fundamental crystal chemistry of the perovskites but also for the discovery of new functional materials.