Abrupt appearance of the domain pattern and fatigue of thin ferroelectric films

We study the domain structure in ferroelectric thin films with a "passive" (nonferroelectric) layer at the interface between the film and electrodes. An abrupt transition from a monodomain to a polydomain state has been found with the increase of the passive layer thickness d. The domain width chang es very quickly at the transition (exponentially with d(-2)). The slope of the hysteresis loop is in agreement with experiment, assuming realistic par ameters of the layer. The slope scales as lid, involving only the propertie s of the layer. We believe that specific properties of the domain structure in ferroelectrics with a passive layer can resolve the lone-standing "para dox of the coercive field.".