由上下电极覆盖的铁电薄膜中最小180度电畴尺寸

在较低的电压下,铁电畴发生反转的性能对于研发高密度铁电存储器是至关重要的．为了实现高密度存储,铁电畴必须做得愈小愈好．然而,当外加电场撤去后,很小的铁电畴是不稳定的,会发生缩小,直致消失,导致存储的信息消失．为解决此问题,发展了一种通用的方法用于决定避免反向反转的铁电畴的尺寸．做为一个例子,确定了由上下电极覆盖的铁电薄膜中最小180度电畴尺寸．该研究可以用于许多相似的问题．     

MINIMUM SIZE OF 180 DEGREE DOMAINS IN FERROELECTRIC THIN FILMS COVERED BY ELECTRODES

Ferroelectric domain switching under low voltage or short pulses is of interest for the development of high-density random access memory (FRAM) devices. Being necessarily very small in size, instability and back switching often occur when the external voltage is removed, which creates serious problems. In this investigation, a general approach to determine the minimum size of ferroelectric domain to avoid back switching was developed, and as an example, a 180°domain in a ferroelectric thin film covered by the upper and lower electrodes was considered in detail. We note that our approach is generally applicable to many other fields, including phase transformation, nucleation and expansion of dislocation loops in thin films, etc.