Temperature and DC bias electric field dependence of piezoelectric ceramics.

摘要

In this research, the temperature and DC bias electric field dependence of different compositions of a widely used piezoelectric material, lead zirconate titanate (PZT), was studied using state-of-the-art instruments for temperature ranging from -165°C to 195°C and for DC bias electric fields varying from -2 MV/m to 2 MV/m. A computer program analysed the impedance or admittance, as a function of frequency, of several soft and hard doped PZT samples, pre-cut to various resonance geometries, while varying the temperature and the DC bias field conditions on the samples. The resonance method analysis allowed the calculation of several piezoelectric, elastic and dielectric constants, as well as the corresponding electromechanical coupling factors for these PZT samples. Upon plotting these material constants as a function of temperature and DC bias fields, abnormal variations, broad peaks and hystereses were observed. The non-linear response of soft and hard doped PZT is discussed with respect to the domain walls dynamics (displacement, clamping and de-pinning) as well as the ceramic crystal structure, grain size (seen with a Scanning Electron Microscope) and internal defects. (Abstract shortened by UMI.)