Ferroelectric domain kinetics in congruent LiTaO3

We present real-time studies of nucleation and growth of 180 degrees ferroe lectric domains in congruent LiTaO3 under an external electric field using optical microscopy. The measured wall velocities are an order of magnitude higher than those reported before using ex-situ techniques. Merger of growi ng domains form serrated fronts which show a further order of magnitude inc rease in wall velocity. A time dependent velocity is required in the Avrami theory to explain the change in domain area versus time at a constant elec tric field. We believe that these features of domain switching must be cons idered when studying ferroelectrics in general.