铁电薄膜平均极化性质的研究

Study on the Average Polarization Property of Ferroelectric Film

是在热力学唯象理论的框架下,研究由两种铁电材料组成的铁电双层膜系统的极化性质.通过引入的两个参量:参量(描述铁电双层膜系统中两种铁电体的物理性能差异)和参量(描述铁电双层膜系统两种铁电体相变温度的差异),研究了不同温度和不同界面耦合系数条件下,铁电双层膜系统平均极化随这两个参量的变化情况.研究表明:参量增大时,铁电双层膜系统的平均极化随之增大.当取固定值时,平均极化随界面耦合系数增大而增大;随着温度t、参量的增大而减小.参量增大时,铁电双层膜系统的平均极化减小.当参量取固定值时,平均极化随着温度t的增大而减小;随着参量、界面耦合系数的增大而增大.

Within the framework of thermodynamic phenomenological theory,the polarization property of the ferroelectric bilayer film consisting of two different ferroelectric materials is studied. Through two parameters introduced,that is,parameter α（ which describes the differences of physical property between two ferroelectrics in the ferroelectric bilayer film）; parameter γ,（ which describes the differences of ferroelectric phase transition temperature between two ferroelectrics in the ferroelectric bilayer film）. Accordingly,the variation of the average polarization of ferroelectric bilayer film with these two parameters under different temperatures and interfacial coupling coefficients is studied,the results indicate that： the average polarization of ferroelectric bilayer film will increase as the parameter α enhances,as α is set a fixed value,the average polarization shows two results： It will increase with interfacial coupling coefficient j enhancing and decrease with the temperature t,parameter γ increasing. When it comes to the parameter γ,the average polarization of ferroelectric bilayer film will decrease as the parameter γ enhances,and the average polarization will similarly shows two results asα is set a fixed value： it will decrease with temperature t increasing and increase with the parameter α and interfacial coupling coefficient j enhancing.