摘要
在平均场近似下,采用横场Ising模型研究自由边界条件下的温度梯度铁电薄膜的极化性质.当温度梯度铁电薄膜采用自由边界条件时,薄膜受热导致晶格沿极化方向膨胀使得赝自旋相互作用系数发生变化,因此,赝自旋相互作用系数应作为坐标的函数.研究表明:考虑赝自旋相互作用系数的变化后,温度梯度铁电薄膜的极化强度和相变温度都较不考虑赝自旋相互作用系数变化的情况有所增加.薄膜始末两赝自旋层的温度比以及薄膜固定端的温度是影响温度梯度铁电薄膜极化性质的两个重要因素.
In the framework of the mean field approximation,a transverse Ising model（TIM） is adopted to analyze the polarization properties of temperature-graded ferroelectric films under free boundary condition.When temperature-graded ferroelectric films are under free boundary condition,due to the expansion along the polarization aroused by heating,pseudo-spins interaction couplings get changing.Hence,the interaction couplings should be considered as a function of coordinate.The results show that considering the variation of pseudo-spins interaction couplings,polarization and phase-transition temperature become larger.The temperature of top layer and the ratio between the top-layer temperature and bottom-layer temperature are the two important factors that influence the polarization properties of temperature-graded ferroelectric films.
出处
《沈阳化工大学学报》
CAS
2010年第3期279-282,共4页
Journal of Shenyang University of Chemical Technology
基金
国家自然科学基金资助项目(10647138)
辽宁省科研基金资助项目(20060667)
关键词
温度梯度
自发极化
相变温度
temperature gradient
spontaneous polarization
phase-transition temperature
