Depoling and fatigue behavior of Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystal at megahertz frequencies under bipolar electric field

摘要

Bipolar electric field induced degradation in 001(c) poled Pb( Mg1/3Nb2/3)O-3-0.29PbTiO(3) (PMN-0.29PT) single crystals was investigated at megahertz frequencies. The electromechanical coupling factor k(t), dielectric constant epsilon(r), dielectric loss D, and piezoelectric constant d(33) were measured as a function of amplitude, frequency, and number of cycles of the applied electric field. Our results showed that samples degrade rapidly when the field amplitude is larger than a critical value due to the onset of domain switching. We define this critical value as the effective coercive field E-c at high frequencies, which increases drastically with frequency. We also demonstrate an effective counter-depoling method by using a dc bias, which could help the design of high field driven devices based on PMN-PT single crystals and operated at megahertz frequencies. Published by AIP Publishing.