Measurement of the Nonlinear Coefficient of a Third-Higher Term in Lead Zirconate Titanate Piezoelectric Ceramics.

Abstract

Fundamental and 3rd-harmonic voltages between a pair of electrodes, appearing due to nonlinearity, were theoretically calculated in a piezoelectric rectangular vibrator which was driven by a sinusoidal constant current having the resonance frequency of length-extensional 1/2λ-mode vibration. The theoretical calculation was performed using the electrical equivalent circuit of a piezoelectric rectangular vibrator. Since the fundamental and 3rd-harmonic voltages were generated with cosine distributions in the sample and the motional impedance to each generated voltage also has a cosine distribution, Millman's theorem was used in the analysis of the fundamental and 3rd-harmonic voltages between a pair of electrodes. This analysis clarifies quantitatively the relationship between the nonlinear voltages between electrodes and a nonlinear coefficient used as a material constant.