Evaluation of the complex material constants of piezoelectric ceramics in the thickness vibration mode

A new noniterative method, for determining the dielectric, piezoelectric and elastic constants, in complex form, for piezoceramic materials, in the thickness extensional mode, was proposed.This method is very flexible, as it is based on the standard approach to determine the elastic stiffness, followed by the measurement of the impedance at two frequencies to calculate the dielectric and piezoelectric constants, by solving a system of two equations.The new method was tested on materials with various thickness coupling factors (kt = 4.5–60%) and mechanical quality factors (Qmt = 20–1600), proving very good accuracy for all of them.The accuracy of standard method was also evaluated for the same materials.