Dynamic process of domain switching in ferroelectric films
Dynamic process of domain switching in ferroelectric films
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DOI：
10.1063/1.1599958
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发表时间：
2003-08
影响因子：
3.2
通讯作者：
Biao Wang;R. Xia;H. Fan;C. Woo
中科院分区：
文献类型：
--
作者：
Biao Wang;R. Xia;H. Fan;C. Woo
本文建立了铁电薄膜电畴变动力学的一般变分公式。通过在朗道自由能展开式中加入动能，得到了二阶含时的Ginzburg-朗道演化方程，该方程可用于分析材料的介电和铁电性质随频率的变化.建立了一个数值模型，计算了畴变过程中极化和电场随时间的变化。作为一个有实际意义的例子，研究了垂直于薄膜表面的180°畴界的铁电薄膜。发现畴变过程分为两个阶段，铁电畴的初始成核和生长，然后通过180°畴壁的侧向运动扩展畴，直到整个带电区域的自发极化反转。
In this article, a general variational formulation is established for the dynamics of domain switching in ferroelectric thin films. By incorporating the kinetic energy in the Landau free energy expansion, we obtain a second-order time-dependent Ginzburg–Landau evolution equation, which can be used to analyze the frequency-dependent dielectric and ferroelectric properties of the materials. A numerical model is developed to calculate the time-dependent polarization and electric-field distribution during the domain switching process. As an example of practical importance, a ferroelectric film with 180° domain boundaries perpendicular to the film surface is studied. Domain switching is found to proceed in two stages, the initial nucleation and growth of the ferroelectric domain, followed by the expansion of the domain through the sidewise motion of the 180° domain walls, until the spontaneous polarization in the entire electrified area is reversed.