Polarity Effects and Charge Liberation in Lead Zirconate Titanate Ceramics under High Dynamic Stress

Abstract

A polarity effect has been observed in dynamically stressed ferroelectric lead zirconate titanate ceramics Pb0.99Nb0.02(Zr0.65Ti0.35)0.98O3, which depends on the motion of the stress wave relative to the direction of remanent polarization. From the observations it is concluded that p-type mobile charge carriers are being liberated at the stress front, which in turn are acted upon by local internal fields. This action causes dielectric degradation when the stress wave travels opposite to the direction of remanent polarization. The charge liberation is attributed to a combination of ionization and failure mechanisms. Graham has reported a similar effect in alpha quartz, in which electrons are liberated.