Evaluation of Electromechanical Coupling Factor for Piezoelectric Materials Using Finite Element Modeling

Abstract

This work uses a finite element modeling method to study the electromechanical coupling factor of piezoelectric materials. Two types of piezoelectric materials were chosen, piezoelectric materials (PZT) and Pb-free piezoelectric materials Ba(Zr0.2Ti0.8)O3-50(Ba 0.7Ca 0.3)TiO3 (BZT -50BCT) that measure the resonance and anti-resonance frequencies for the calculation of the planar and thickness coupling factor values. For PZT5A, in rad ial v ibration mode, these frequencies were 178 and 211 kHz, and in thickness mode, 2.182 M Hz, respectively. For the BZT-50BCT, the frequencies were 224 and 250 kHz, and in thickness mode, 2.539M Hz, respectively. The coupling factor values were 0.57 (kp) and 0.33 (kt) for PZT5A and 0.50 (kp) and 0.28 (kt) for BZT-50BCT, respectively.