Field induced strains in antiferroelectrics

Lead zirconate-based materials with a slight content of titanium undergo an antiferroelectric-ferroelectric phase transition when an electric field is applied. The strains accompanying this field-induced transition are gigantic in comparison with the strain change in the antiferroelectric or ferroelectric state. In the case of components with a higher titanium content, the material will memorize the ferroelectric state, even under zero-field conditions, once the ferroelectric phase has been induced. The initial antiferroelectric phase is recovered with application of a small reverse bias or a thermal annealing. A mechanical clamp and a latching relay are typical applications of the shape memory ceramics.