Domain nucleation and relaxation kinetics in ferroelectric thin films

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