Temperature- and Stress-Dependent Electromechanical Response of Porous Pb(Zr,Ti)O3

The small-signal direct piezoelectric coefficient and dielectric permittivity are characterized as a function of temperature from 25 to 450 degrees C and uniaxial compressive stress up to 80 MPa in porous Pb(Zr,Ti)O-3 (PZT; 10, 20, 30, 40, and 50 vol% porosity). Results show retention of piezoelectric response throughout the temperature range with increasing porosity up to 30 vol%, above which a subsequent decrease is observed. Similarly, increasing porosity did not result in a significant change of the depolarization temperature, although a slight increase in the Curie point is observed with increasing porosity. Macroscopic experimental results are discussed together with microcomputed tomography, which shows the 3D pore structure. These results are important for sensing applications that operate at elevated temperatures and apply compressive stress to the electroactive element.