Modeling of nonlinear phenomena in ferroelectric solids
Modeling of nonlinear phenomena in ferroelectric solids
Associated people
Abstract
When applied to high electrical and/or mechanical fields, the constitutive response of ferroelectric materials becomes highly nonlinear and expresses itself in terms of e.g. dielectric-, butterfly-, and ferroelastic-type hysteresis. This is due to the fact that high electro-mechanical fields induce internal switching of the existing spontaneous polarization within the material. Such switching is utilized during the plarization process of a polycrystalline ferroelectric in order to produce a macroscopically coupled functional electroceramic. On the other hand, during the operation of a poled piezoelectric device, high internal fields can arise and lead to electrically and mechanically induced switching. These fields influence the functionality of the ceramic in such a way that they can lead to a partial or complete depolarization of the material.
The research project deals with the continuum mechanical modeling of electrically and mechanically induced switching from a microscopic view point. The modeling is based on a fully tetragonal representation of the material including an energy-based concept for the incorporation of ferroelectric and ferroelastic switching.
References