再论铁电体的热-电-力耦合内场

Thermo-electro-mechanically coupled internal fields of ferroelectrics

基于铁电体的热-电-力耦合内场的性质研究,本文进一步探讨其内场的其他性质。由于力学因素使问题变得复杂,故忽略力学因素,以简化后的物性方程为出发点,以一维体系为例推导了内电势与温度之间的关系,计算了内电场和有关的热力学力,给出了确定内电势函数中的积分常数的方法。研究表明,内电势是温度的线性函数,其中的积分常数可由内电场、温度梯度及输运系数确定。这有助于更深入地了解铁电-顺电相变,特别是一级铁电-顺电相变的内在规律。

Based on the properties studies of the thermo-electro-mechanically coupled internal fields of ferroelectrics,the other properties of these internal fields are further discussed in this paper.The mechanical factors are neglected because they make the problem more complicated.Taking the simplified physical property equation as the starting point,the relation between the internal electric potential and the temperature is derived by taking a one-dimensional system as an example.The internal electric field and the relevant thermodynamic forces are calculated,and the method for determining the integral constants in the internal electric potential function is given.It is shown that the internal electric potential is a linear function of the temperature,and the integral constants can be determined by the internal electric field,the temperature gradient and the transport coefficients.It is helpful to understand the inherent law of ferroelectric-paraelectric phase transition,especially the first order ferroelectric-paraelectric phase transition.