Abstract
Growth conditions for repolarization nuclei in Pb(Zr1-xTix)O3 polycrystalline ferroelectric films with frequency dependence of coercive field of ln(ν/ν0)∼1/Ec2 are studied. The main contribution to polarization switching is provided by the formation of nuclei of a critical size by means of thermal fluctuations. However, near electrode edges the growth of nuclei of a subcritical size is shown to be possible. Free energy release accompanying the growth of a nucleus does not depend on its size. This enables rapid growth of nuclei near electrode edges and explains experimentally observed dependence of the limiting frequency for polarization switching on the electrode geometry.