The effect of temperature and loading frequency on the converse piezoelectric response of soft PZT ceramics

The converse piezoelectric coefficient d ₃₃ of soft PZT ceramics was measured from 20 °C to 150 °C under different loading frequency. Results showed that in the tested temperature range, the evolution of d ₃₃ obeys the Rayleigh-law behavior. The influence of temperature on d ₃₃ is a little complicated. For instance, the maximum d ₃₃ was observed at 150 °C when the applied electric field E was at 0.1 kV mm⁻¹. When E increased to 0.3 kV mm⁻¹ and 0.4 kV mm⁻¹, the maximum d ₃₃ was observed at 120 °C and 100 °C, respectively. Such behaviors are rationalized by the evolution of the Rayleigh parameters d _init and α. For d _init, it increases as temperature increases. While for α, it first increases and then decreases with the increase of temperature due to the evolution of the spontaneous strain and the volume of the switched domains. In the tested loading frequency, d ₃₃ decreased linearly with the logarithm of the frequency of electric field. With the increase of temperature, the influence of frequency on d ₃₃ gradually weakened, implying that at high temperature, the motion of domain walls became active and the pinning effect of defects nearly disappeared. (paper)