温度梯度铁电材料热释电性质的微观机制研究

Reaearch on the Microscopic Mechanism of the Pyroelectric Properties of Temperature Gradient Ferroelectric Materials

在平均场近似的理论框架下,采用拓展的横场伊辛模型理论,引入分布函数描述材料内部的量子起伏效应和温度梯度导致的铁电畸变,探讨影响温度梯度铁电材料热释电性质的微观机制。研究表明量子起伏效应和铁电畸变是影响铁电材料热释电性质的两个重要因素。随着量子起伏效应的增强,热释电系数峰值逐渐下降,但对热释电峰值出现的位置影响并不显著;铁电畸变的存在,大大提高了材料热释电系数的峰值;温度梯度铁电材料内第一层级发生相变的时刻是影响材料热释电峰出现的最显著的因素。

Under the theoretical framework of mean field approximation,the extended transverse Ising model theory is adopted,a distribution function is introduced to describe the quantum fluctuation effect in the material and ferroelectric distortion caused by temperature gradient,and the micro mechanism that affects the pyroelectric properties of temperature gradient ferroelectric materials is explored.Research has shown that the quantum fluctuation effect and ferroelectric distortion are two important factors affecting the pyroelectric properties of ferroelectric materials.As the quantum fluctuation effect increases,the peak value of the pyroelectric coefficient gradually decreases,but it has no significant effect on the position of the peak value of the pyroelectric coefficient.Due to the presence of ferroelectric distortion,the peak value of the pyroelectric coefficient of the material is greatly increased,and the moment of phase transition in the first layer of temperature gradient ferroelectric materials is the most significant factor affecting the appearance of the peak of the pyroelectric coefficient of the material.