铁电双层膜中的极化翻转与极化梯度

The polarization and polarization-gradiend of ferroeleetric bilayers

从Ginzburg-Landau方程出发,引入自发极化梯度项,研究了铁电双层膜的电滞回线,采用平均极化来反映膜的性质.结果表明:在场强较大的情况下,两膜的平均极化与电场方向一致;在场强较小的情况下(E=-8.00×107V·m-1),膜1发生极化翻转,界面耦合占主导地位.这些新现象为设计具有多个存储态计算机存储单元提供了可能.

Add the term of self-polarization-gradient to the equation of Ginzburg-Landau, this paper has studied the hysteresis loop of ferroelectric bilayers, and adopted the average polarization to reflect the character of the bilayers. The result shows that in strong electric field (E) average polarization's direction goes along with that of E. In weak E where E equas to-8.00×107 V·m-1, the polarization-flop of layer 1 happens. In this case, the exchange coupling at interfase is dominating. This new phenomenon suggests that it is possible to design computer assembled with multicell by means of the ferroelectric bilayers and superlattices with polarization-gradient.