Velocity of domain-wall motion during polarization reversal in ferroelectric thin films: Beyond Merz's Law
Velocity of domain-wall motion during polarization reversal in ferroelectric thin films: Beyond Merz's Law
复制标题
DOI：
10.1103/physrevb.91.054104
复制
发表时间：
2015-02-09
影响因子：
3.7
通讯作者：
Zhu, Yimei
中科院分区：
文献类型：
--
作者：
Meng, Qingping;Han, Myung-Geun;Zhu, Yimei
畴壁（DWs）的运动对铁电材料的开关动力学至关重要。仅依赖于外加电场的默兹定律不能解释最近在FE薄膜上的实验观察，因为这些实验表明DW速度不仅取决于外加电场的强度，还取决于反转域的大小。在本文中，我们推导了一个模型来理解控制FE DWs速度的主导因素。我们的计算表明，DW速度不仅是电场强度的函数，而且随着测量特征时间的增加或生长域的大小呈指数衰减。我们的观察可以很自然地解释文献中报道的巨大变化，超过15个数量级，在实验中测量的DW速度和FE畴条纹形状的形成。
The motion of domain walls (DWs) is critical to switching kinetics in ferroelectric (FE) materials. Merz's law, dependent only on the applied electric field, cannot explain recent experimental observations in FE thin films because these experiments showed that the DW velocity depends not only on the strength of the applied electric field but also on size of the reversal domain. In this paper, we derive a model to understand the dominant factors controlling the velocity of FE DWs. Our calculations reveal that the DW velocities are not only a function of the strength of the electric field but also decay exponentially with the increasing characteristic time of the measurement or the size of the growing domain. Our observations can naturally explain the gigantic variation reported in the literature, over 15 orders of magnitude, in the experimentally measured DW velocities and the formation of the stripe shape of FE domains.