...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Physics, D. Applied Physics: A Europhysics Journal >Domain wall contribution to the nonlinear dielectric response: effective potential model
【24h】

Domain wall contribution to the nonlinear dielectric response: effective potential model

机译：畴壁对非线性介电响应的贡献：有效电势模型

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Domain wall displacement has an important contribution to the different nonlinear dielectric responses observed in ferroelectrics. For a moderated alternating electric field, domain walls perform a small displacement around their equilibrium positions. Such motion of the domain walls can be modelled as a body moving in a viscous medium under the action of an effective potential W(l). From this model the dispersion relationships are derived. The exact expression for the effective potential is found assuming that the dielectric permittivity depends on the electric field strength as epsilon proportional to 1/(alpha + beta E-2). The effect of multidomain structure and polarization hysteresis are introduced through the effective field approximation E-eff equivalent to E + kappa P(E). An important merit of the model is that it allows the simulation of transient polarization processes for the arbitrary input signal, predicting a power law for the polarization and depolarization currents. An analytic expression is found for the dependence of the permittivity on the electric field strength that correctly reproduces its hysteretic behaviour. The polarization loop and nonlinear dielectric response for subswitching the alternating electric field are simulated and compared with experimental data obtained from PZT thin films. It was observed that the simulated dielectric loss was lower than the experimental one, which can be explained as a result of the interaction of domain walls with defects. Point defects are introduced into the model as a perturbation of the effective potential, showing the dependence of the dielectric loss on the concentration of the defects.
机译：畴壁位移对铁电中观察到的不同非线性介电响应具有重要贡献。对于缓和的交变电场，畴壁在其平衡位置周围执行较小的位移。畴壁的这种运动可以被建模为在有效电势W（1）的作用下在粘性介质中运动的物体。从该模型得出色散关系。假设介电常数取决于ε/ 1 /（α+βE-2）的电场强度，则可以找到有效电势的精确表达式。通过等效于E + kappa P（E）的有效场近似E-eff引入多域结构和极化磁滞的影响。该模型的一个重要优点是，它可以模拟任意输入信号的瞬态极化过程，从而预测极化电流和去极化电流的功率定律。对于介电常数对电场强度的依赖性，可以找到一个解析表达式，可以正确地再现其磁滞行为。模拟了极化环和用于子电场交变的非线性介电响应，并将其与从PZT薄膜获得的实验数据进行了比较。观察到，模拟的介电损耗低于实验损耗，这可以解释为畴壁与缺陷相互作用的结果。将点缺陷作为有效电势的扰动引入模型中，显示出介电损耗对缺陷浓度的依赖性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号