Electrostriction
Electrostriction describes the deformation of a dielectric medium as a function of an applied electric field . In the usual definition, the term electrostriction only refers to the part of the effect in which the deformation is independent of the direction of the applied field and proportional to the square of the field. This distinguishes electrostriction from the inverse piezoelectric effect , which describes the linear response of deformation to the field.
The electrostriction is described by the electrostrictive coefficients. A distinction is made between electrostrictive distortion coefficients, which describe the reaction of the distortion to the electric field,
and electrostrictive stress coefficients, which describe the reaction of the mechanical stress to the electric field:
First order effects are described by the piezoelectric coefficients.
However, the term electrostriction is often used improperly in the literature. In its general formulation, electrostriction describes any interaction between the deformation of a dielectric medium and an applied field. In this use, the electrostriction then includes the inverse piezoelectric effect , in which a change in volume is brought about by an applied voltage.
Electrostriction can cause noises when there are strongly changing electrical fields on a dielectric (e.g. in a capacitor) - similar to how noises can be caused by magnetostriction on ferromagnetic materials (e.g. in coil cores) in changing magnetic fields.
Individual evidence
- ^ Robert E. Newnham: Properties of Materials: Anisotropy, Symmetry, Structure . Oxford, New York 2005, ISBN 0-19-852075-1 , limited preview in Google Book Search.
- ↑ Kai Borgeest: Electronics in automotive engineering . Vieweg + Tebner, Wiesbaden 2010, ISBN 978-3-8348-0548-5 , limited preview in the Google book search