The novel mechanism for field-enhanced effect of the dielectric response in relaxor KTN crystal
The novel mechanism for field-enhanced effect of the dielectric response in relaxor KTN crystal
复制标题
DOI：
10.1007/s11082-022-04106-8
复制
发表时间：
2022-09
影响因子：
3
通讯作者：
Jianwei Zhang;Xiaoping Du;Jiguang Zhao;Yongsheng Duan;Xuping Wang;Z. Liu;Hang Chen
中科院分区：
文献类型：
--
作者：
Jianwei Zhang;Xiaoping Du;Jiguang Zhao;Yongsheng Duan;Xuping Wang;Z. Liu;Hang Chen
最近的实验表明，介电对偏置电场的响应具有明显的频率依赖性，主要表现为强场增强效应和弱场增强效应，并揭示了这种行为背后的新机制。我们发现强场增强效应是由场诱导重排产生的机电耦合谐振引起的。考虑到固有的多尺度不均匀性，KTN晶体中分布着多尺度极性纳米区域，我们发现多尺度PNR与电场之间的共振引起的增强振动可以增加介电常数，从而产生弱场增强效应。此外，多尺度不均匀性还会导致介电响应电场的局部非单调行为。我们的发现为多尺度 PNR 的场驱动动力学提供了更好的理解，并为开发有前景的电光器件、偏转器和可调器件铺平了道路。
Recent experiment reveals that the dielectric response to the bias electric field has obvious dependence on the frequency, which is mainly manifested in strong field-enhanced effect and weak field-enhanced effect, and reveals the novel mechanism behind this behavior. We find that the strong field-enhanced effect is caused by electromechanical coupling resonance originating from field-induced rearrangement. Considering inherent multiscale inhomogeneity, multiscale polar nanoregions distribute in the KTN crystal, and we find that the dielectric permittivity can be increased by enhanced vibration caused by the resonance between the multiscale PNRs and electric field, resulting in weak field-enhance effect. In addition, the multiscale inhomogeneity can also cause local nonmonotonic behavior of dielectric response to the electric field. Our finding provides a better understanding for the field-driven dynamics of the multiscale PNRs and paves the way to develop promising electro-optic devices, deflectors and tunable device.