Domain nucleation and relaxation kinetics in ferroelectric thin films

The time-dependent relaxation of the remanent polarization in epitaxial lead zirconate titanate (PbZr0.2Ti0.8O3) ferroelectric thin films, containing a uniform two-dimensional grid of 90 degrees domains (c axis in the plane of the film), is examined using piezoresponse microscopy. The 90 degrees domain walls preferentially nucleate the 180 degrees reverse domains during relaxation, with a significant directional anisotropy. Relaxation occurs through the nucleation and growth of reverse domains, which subsequently coalesce and consume the entire region as a function of time. (C) 2000 American Institute of Physics. [S0003-6951(00)03444-6].