Correlated Functional Oxides: Nanocomposites and Heterostructures
Correlated Functional Oxides: Nanocomposites and Heterostructures
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DOI：
10.1007/978-3-319-43779-8
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
H. Nishikawa;N. Iwata;T. Endo;Y. Takamura;Gun-hwan Lee;P. Mele
中科院分区：
文献类型：
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作者：
H. Nishikawa;N. Iwata;T. Endo;Y. Takamura;Gun-hwan Lee;P. Mele
用解析和数值方法研究了固定在衬底上的铁电（001）取向薄膜的性质。重点是四畴，多畴，铁电相，使用三畴结构，如实验观察到的，而不是在早期文献中使用的两畴结构。先前使用的，非常严格的边界条件，所产生的域壁，放松，创造更多的模式的能量松弛。有人认为，这种方法给出了一个更现实的描述的钳位铁电薄膜。结果表明，对于铁电氧化物PbZr 1-xTixO 3，在很宽的衬底诱导应变范围内存在四畴，多畴相，对应于体相图的四畴侧。在块状菱面体侧存在多畴菱面体相。相-温度图，和铁电，介电，压电性能以及晶格参数计算作为衬底诱导应变和外加电场的函数。解析公式允许分解成三个不同的原因：畴壁运动，场致弹性效应，和压电效应的数值获得的值的这些属性。结果表明，在外加电场作用下，面内取向畴的畴壁运动和极化旋转对薄膜的性能贡献最大，而面外取向畴的贡献很小。
The properties of a ferroelectric, (001)-oriented, thin film clamped to a substrate are investigated analytically and numerically. The emphasis is on the tetragonal, polydomain, ferroelectric phase, using a three domain structure, as is observed experimentally, instead of the two-domain structure used in earlier literature. The previously used, very restrictive set of boundary conditions, arising from the domain walls, is relaxed, creating more modes for energy relaxation. It is argued that this approach gives a more realistic description of the clamped ferroelectric film. It is shown that for the ferroelectric oxides PbZr1−xTixO3,the tetragonal, polydomain phase is present over a wide range of substrate induced strains for, corresponding to the tetragonal side of the bulk phase diagram. A polydomain, rhombohedral phase is present for, at the bulk rhombohedral side. Phase-temperature diagrams, and ferroelectric, dielectric, and piezoelectric properties as well as lattice parameters are calculated as function of substrate induced strain and applied field. The analytical formulation allows the decomposition of the numerically obtained values of these properties into three different causes: domain wall motion, field induced elastic effects, and piezoelectric effects. It is found that domain wall motion and polarization rotation of the in-plane oriented domains under an applied field contribute most to the properties, while the out-of-plane oriented domains hardly contribute.