Question

Difference between piezoelectric pyroelectric and ferroelectric materials

Answer 1

Piezoelectrics are materials that are capable of creating electricity when they are subjected to a mechanical stress. They will also work in reverse, generating a strain by the application of an electric field. In these materials, the coupling between the mechanical and electrical energy results in an electric polarization when stress is applied. 

Pyroelectricity is the ability of certain materials to generate an electrical potential when they are heated or cooled. As a result of this change in temperature, the positive and negative charges move towards the opposite ends through migration as the material becomes polarised and hence, an electrical potential is established. The polar axis of a pyroelectric material allows a net polarization when the temperature is changed.

Ferroelectricity is a characteristic of certain materials that have a spontaneous electric polarization that can be reversed by the application of an external electric field. The term is analogous to ferromagnetism, in which a material exhibits a permanent magnetic moment.

Ferroelectrics are a special subset of pyroelectrics, in that their polarization can be reversed on the application of an electric field. All ferroelectrics are both pyroelectric and piezoelectric.