On the Dislocation Contribution to the Dielectric Loss in the Materials with Piezoelectric Properties

Abstract

A variable electric field is applied to a crystal. This field gives rise – through the piezoelectric coupling – to the variable mechanical stresses. Then the dislocations in the crystal will be driven by Peach-Koehler force and will start moving, dissipating the external field energy. Connection of the electric field energy dissipated per unit time with the internal friction is found. The case of resonant loss (Granato-Lucke model) is considered. The loss related to this mechanism to be at frequencies of megahertz range. The relaxation processes being responsible for the Bordoni and Hasiguti peaks also are considered. The use of obtained equations makes it possible to distinguish the dislocation contribution to both dielectric loss and dielectric dispersion and, therefore, to derive additional information about the crystal structure in a sufficiently simple way in terms of only one method.