Interface effects in ferroelectric PbTiO3 ultrathin films on a paraelectric substrate.
Interface effects in ferroelectric PbTiO3 ultrathin films on a paraelectric substrate.
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DOI：
10.1103/physrevlett.96.137603
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发表时间：
2006-01
影响因子：
8.6
通讯作者：
M. Sepliarsky;M. Stachiotti;R. Migoni
中科院分区：
文献类型：
--
作者：
M. Sepliarsky;M. Stachiotti;R. Migoni
使用原子间势方法和符合第一原理计算的参数，研究了沉积在 SrTiO3 基底上的 PbTiO3 超薄膜的铁电行为的界面效应。我们发现薄膜-基底界面上原子位移的相关性对于几个晶胞厚度的薄膜中铁电态的稳定至关重要。我们表明，出现自发极化域状态的最小薄膜厚度不是铁电薄膜的固有属性，而是取决于顺电基板的极化率。我们还观察到基板显示出具有不寻常振荡行为的诱发极化。
Interface effects on the ferroelectric behavior of PbTiO3 ultrathin films deposited on a SrTiO3 substrate are investigated using an interatomic potential approach with parameters fitted to first-principles calculations. We find that the correlation of atomic displacements across the film-substrate interface is crucial for the stabilization of the ferroelectric state in films a few unit cells thick. We show that the minimum film thickness for the appearance of a spontaneous polarized domain state is not an intrinsic property of the ferroelectric film but depends on the polarizability of the paraelectric substrate. We also observe that the substrate displays an induced polarization with an unusual oscillatory behavior.