Ferroelectric materials have seen applications as actuators (the fuel injection system in the latest BMWs), sensors (naval sonar systems), and ferroelectric nonvolatile random access memories (FRAMs). For actuators and sensors it is the piezoelectric behavior of these materials that is exploited, while for FRAMs the ability of the material to “switch” polarization states is the essential feature for the application. 

Polarization switching-induced shielding or anti-shielding of an electrically permeable crack in a mono-domain ferroelectric material with the original polarization direction perpendicular to the crack is simulated by a phase field model based on the time-dependent Ginzburg-Landau equation. The domain wall energy and the long-range mechanical and electrical interactions between polarizations are taken into account.