3-D ferroelectric domain reversal mechanism

Abstract

A three-dimensional (3-D) time-dependent domain reversal mechanism in ferroelectrics has been proposed based on the domain shape evolution analysis, which can also be extended to study the ferroelectric domain breakdown (FDB) phenomenon induced by a high inhomogeneous AFM-tip electric field. It has been found that FDB can be divided into three stages: The first is the nucleation process, in which the aspect ratio of critical conic nucleus is kept constant. With the increase of domain radius, the formation of depolarization field commences at the end of the nucleation stage, where the aspect ratio abruptly decreases to an equilibrium value. Subsequently, domain breakdown would occur in a cylinder-shaped mode if there is substantial forward driving force. This suggested the essential function of the characteristic equilibrium aspect ratio formed in the second stage to initialize FDB phenomenon, that is, it cannot be too small to reverse the direction of forward driving force. Moreover, LiNbO3 ferroelectrics are found to possess the lowest critical tip voltage to cause FDB compared with other ferroelectrics. Finally, the analysis of experimental data also shows well agreement of our proposed mechanism.