Electrostrictive effect


The generation of strain in a dielectric material induced by an electric field.

The model of crystal lattice of cations and anions bonded with one another by springs is often well applied to ceramics. If an electric field is applied to a material that is not conductive, the cations in the material are attracted in the direction of the electric field whereas the anions are attracted in the opposite direction, with this inducing a stress to deform the crystal lattice. The strain induced by the electric field is classified into two by the property of the inter-ionic springs determined by the crystalline structure. In a symmetric crystal, much part of extension and contraction is cancelled between neighboring springs so that the whole crystal shows little strain. Although, to be accurate, the anharmonicity of the springs causes a strain that is proportional to the square of the electric field strength. This is known as the electrostrictive strain effect. Whereas an asymmetric crystal shows a strain that is proportional to the electric field strength, which is called the reverse piezoelectric effect.


[Related Terms]
Piezoelectric effect