小温差情况下温度梯度铁电材料零极化偏移现象的理论验证

Theoretical Verification of the Zero Polarization Offset in Temperature-graded Ferroelectric Materials in the Case of Small Temperature Difference

采用平均场近似下的横场伊辛模型理论,引入描述铁电畸变的分布函数,同时考虑量子起伏效应,研究了温度梯度铁电材料的极化偏移特性,重点针对小温差情况下温度梯度铁电材料极化偏移消失的实验现象进行了理论验证。研究表明,温度梯度的存在导致了材料内部的极化强度的梯度分布,量子起伏效应对温度梯度铁电材料的性质有十分重要的影响,本工作关于温度梯度铁电材料极化偏移的研究结果与实验研究取得了定性一致的结论。当同时在考虑铁电畸变和量子起伏效应时,小温差情况下温度梯度铁电材料极化偏移消失的实验现象得以验证。

A transverse Ising model in the framework of the mean field approximation was adopted.A distribution function was introduced to describe the ferroelectric distortion,and the quantum fluctuation effect was considered at the same time.The pro-perties of polarization offset in temperature-graded ferroelectric materials were investigated.The disappearance of polarization offset in temperature-graded ferroelectric materials in the case of small temperature difference in experiment was mainly theoretically verified.The results show that the temperature gradients lead to the graded distribution of polarization in materials.Quantum fluctuation effect has very important influence on properties of temperature-graded ferroelectric materials.The results of polarization offsets in this paper are in qualitatively accordance with the experimental research.When ferroelectric distortion and quantum fluctuation effects are both considered,the disappearance of polarization offset in temperature-graded ferroelectric materials in the case of small temperature difference in experiment is theoretically verified.