Ferroelectricity

The ferroelectroelasticity and ferroelectricity phenomena are related to phase transitions in materials. In its ferroelectric phase, the material exhibits spontaneous polarization, so that it is constituted of domains with nonzero polarization even at zero applied field. This is similar to permanent magnetism in ferromagnetics, which explains the name used for such materials. Electrostriction in ferroelectroelastic materials can be related to the domain rotation. Thus, the applied electric field can both rearrange the domains resulting into the net polarization and rotate the domains mechanically. Thus, the material extends in the direction of the electric field and contracts in the direction perpendicular to the field. The domain rotation can be affected by an applied mechanical stress, which also results into the effective polarization. At very large electric fields, the electrostrictive effect saturates, as all ferroelectric domains in the material are aligned along the direction of the applied field. Domain wall interactions can also lead to a significant hysteresis in the polarization and strain.

Many piezoelectric materials exhibit such nonlinear ferroelectroelastic behavior at large applied electric fields.