Theory and Neutrons Combine To Reveal a Family of Layered Perovskites without Inversion Symmetry
Theory and Neutrons Combine To Reveal a Family of Layered Perovskites without Inversion Symmetry
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DOI：
10.1021/acs.chemmater.7b03604
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发表时间：
2017-10
影响因子：
8.6
通讯作者：
Tong Zhu;T. Cohen;A. Gibbs;Weiguo Zhang;P. Halasyamani;M. Hayward;N. Benedek
中科院分区：
文献类型：
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作者：
Tong Zhu;T. Cohen;A. Gibbs;Weiguo Zhang;P. Halasyamani;M. Hayward;N. Benedek
最近的一系列理论研究预测了层状钙钛矿中存在新的极性材料，包括双层Dion-Jacobson相。这些预测为Dion-Jacobson相晶体化学的基础研究及其在下一代存储器和低功耗电子器件中的应用开辟了令人兴奋的新机会。然而，除了一些罕见的例外，所有已知的双层dionjacobson相都是非极性的。我们使用综合的理论-实验方法来证明，以前合成并表征为非极性的几个Dion-Jacobson相实际上是极性的。另外的理论计算表明，这些材料的极性相是通过一种杂化的反常或三线性耦合机制出现的。最后，我们的工作强调了中子衍射在表征双层Dion-Jacobson相结构中的关键作用。
A flurry of recent theoretical studies have predicted the existence of new polar materials among several families of layered perovskites, including the double-layered Dion–Jacobson phases. These predictions have opened up exciting new opportunities for both fundamental studies of the crystal chemistry of Dion–Jacobson phases and their application as components in next-generation memories and low-power electronic devices. However, with some rare exceptions, all known double-layered Dion–Jacobson phases are nonpolar. We use an integrated theoretical–experimental approach to show that several Dion–Jacobson phases that have previously been synthesized and characterized as nonpolar are in fact polar. Additional theoretical calculations reveal that the polar phases of these materials emerge through a hybrid improper or trilinear coupling mechanism. Finally, our work has highlighted the critical role of neutron diffraction in characterizing the structures of double-layered Dion–Jacobson phases, which are typifie...