Non-180° domain contribution in electric-field-induced strains of PZT ceramics measured by a Mach-Zehnder interferometer

In order to evaluate the contribution of the non-180 degrees domain reorientation in the electric-field-induced strains of PZT ceramics, a Mach-Zehnder interferometer was constructed and the electric-field-strain of PZT ceramics was measured as a function of frequency. The performance of the interferometer was confirmed using a LiNbO3 single crystal and PZT ceramics. The piezoelectric constant of PZT ceramics determined by the interferometer well agreed with that determined by the resonance method and the result of LiNbO3 single crystal was also approximately consistent with the literature. The resolution of the interferometer was about 0.01 nn. The electric-field-induced strain curve showed a hysteresis under high electric fields and low frequencies. The apparent piezoelectric constant determined from the electric-field-induced strain increased with decreasing frequency under high electric fields. These behaviors were interpreted as the effect of non-180 degrees domain reorientation.