PHASE FIELD STUDY OF POLARIZATION VORTEX IN FERROELECTRIC NANOSTRUCTURES
PHASE FIELD STUDY OF POLARIZATION VORTEX IN FERROELECTRIC NANOSTRUCTURES
复制标题
DOI：
10.1142/s2010135x12410020
复制
发表时间：
2012-04-01
影响因子：
3.1
通讯作者：
Zhang, Tong-Yi
中科院分区：
文献类型：
--
作者：
Wang, Jie;Zhang, Tong-Yi
铁电纳米结构由于其独特的物理性质和在存储器件和纳机电系统中的潜在应用而引起人们的广泛关注。研究发现，低维铁电体，如铁电纳米点、铁电纳米管和铁电薄膜，由于强退极化场和尺寸效应，表现出极化涡旋或类涡旋畴结构。极化涡旋被认为是铁电体中不同于直线极化序的一种新的环形序。这种材料的涡旋极化态是可调的，并且可以从一种状态转换到另一种状态，这在下一代铁电存储器中具有潜在的应用价值。本文简要回顾了铁电纳米结构中极化涡旋相场研究的最新进展。首先介绍了基于Landau-Devonshire理论的铁电体均匀体相热力学。为了描述铁电体中的非均匀极化分布，考虑了界面热力学，建立了含时的Ginzburg-Landau方程组形式的相场模型。
Ferroelectric nanostructures are attracting considerable attention due to their unusual physical properties and potential applications in memory devices and nanoelectromechanical systems. It has been found that low-dimensional ferroelectrics, such as ferroelectric nanodots, ferroelectric nanotubes and ferroelectric thin films, exhibit polarization vortices or vortex-like domain structures due to the strong depolarization field and the size effect. The polarization vortex is regarded as a new toroidal order in ferroelectrics which is different from the rectilinear order of polarization. The vortex states of polarization are bistable and can be switched from one state to the other, which holds the potential application in next generation ferroelectric memories. This paper briefly reviews the recent work on the phase field studies of polarization vortex in ferroelectric nanostructures. The homogeneous bulk thermodynamics of ferroelectrics is first introduced based on the Landau-Devonshire theory. To describe the inhomogeneous polarization distribution in ferroelectrics, the phase field model including interface thermodynamics is then presented in the form of time-dependent Ginzburg-Landau equations.