Random-field model for ferroelectric domain dynamics and polarization reversal

A new concept of polarization reversal and domain dynamics in modified ferr oelectrics is presented. Accordingly, clusters with a reversed polarization within ferroelectric domains are nucleated under applied field in the vici nity of random fields around quenched defects. The random fields significan tly lower the activation barrier required for nucleation, thus controlling the kinetics of polarization reversal and domain dynamics. In this model, p olarization switching occurs by the breakdown of ferroelectric long-range o rder, through a polar cluster state. (C) 2001 American Institute of Physics . [S0021-8979(01)00601-6].