# Difference between revisions of "Piezoelectricity"

### From Online Dictionary of Crystallography

Piezoélectricité (Fr). Piezoelectrizität (Ge). Piezoelectricidad (Sp).

## Definition

Piezoelectricity is the property presented by certain materials that exhibit an electric polarization when submitted to an applied mechanical stress such as a uniaxial compression. Conversely, their shape changes when they are submitted to an external electric field; this is the inverse piezoelectric effect. The piezoelectric effect and the inverse efect are described by third-rank tensors.

## Piezoelectric point groups

The appearance of piezelectricity is compatible with the symmetry properties of the non-centrosymmetric point groups, with the exception of 432. The 20 piezoelectric point groups are therefore:

1, 2, m, 222, 2mm,

3, 32, 3m, 4, ${\bar 4}$,422, 4mm, ${\bar 4}$2m, 6, ${\bar 6}$,622, 6mm, ${\bar 6}$2m

23, ${\bar 4}$3m

## History

It is considerations of symmetry that led the brothers Jacques (1855-1941) and Pierre Curie (1859-1906) to the discovery of piezoelectricity on materials such as tourmaline, quartz, boracite, sodium chlorate, Rochelle salt (Curie J. and Curie P., 1880, C. R. Acad. Sci. Paris, 91, 294-295, Développement, par pression, de l'électricité polaire dans les cristaux hémièdres à faces inclinées. The inverse piezoelectric effect was predicted by Lippmann G., 1881, Ann. Chim. Phy. 24, 145-178, Principe de conservation de l'électricité and discovered by Curie J. and P., 1881, C. R. Acad. Sci. Paris, 93, 1137-1140 , Contractions et dilatations produites par des tensions électriques dans les cristaux hémièdres à faces inclinées.