Temperature dependence piezoelectric properties of 0.78PMN-0.32PT ceramics

Abstract

The temperature dependence piezoelectric properties of 0.78PMN-0.32PT ceramics were studied. The results show that the planar coupling coefficient Kp keeps almost unchanged from room temperature to 90°C, and drops rapidly at temperature regions from 100°C to 130°C. It drops slowly at 130–150°C. Qm reaches minimum values at about 90–100°C, and maximum value at about 140–150°C. This phenomenon can be attributed to the phase transition in this composition. The rhombohedra1 phase changes to tetragonal phase at about 90°C, and tetragonal phase changes to cubic at about 150°C.