Enhanced temperature stability and electrical performances of PZT-based piezoelectric ceramics for high-temperature ultrasonic transducer application

To address the inherent trade-off between piezoelectric performance and temperature stability in Pb(Zr,Ti)O 3 (PZT)-based ceramics for ultrasonic transducer in high-temperature applications, a series of (Pb 0.985 Sm 0.01 )(Zn 0.067 Nb 0.133 Zr 0.8− x Ti x )O 3 (PSZNZ 0.8− x T x , x  = 0.36, 0.37, 0.375, 0.38, 0.39) piezoelectric ceramics were synthesized via the traditional solid-state reaction method. The influence of the Zr/Ti ratio on the crystal structure, microstructure, electrical properties, and temperature stability of these ceramics was rigorously evaluated. With the increase in Ti content, the dominant crystal structure of PSZNZ 0.8− x T x ceramics changes from the rhombohedral (R) phase to the tetragonal (T) phase, and a morphotropic phase boundary (MPB) is formed in the PSZNZ 0.42 T 0.38 ceramic, which exhibits optimal piezoelectric performance ( d 33  ~ 630 pC/N, k p  ~ 70.1%, T C  ~ 310 °C). Notably, the PSZNZ 0.42 T 0.38 ceramic demonstrates excellent temperature stability within the 20–200 °C range: Its remnant polarization ( P r ) and positive strain ( S pos ) exhibit relative change rates of < 35% and < 25%, respectively, while d 33 remains above 600 pC/N with a relative change rate of < 15%. The ultrasonic transducer fabricated with the PSZNZ 0.42 T 0.38 ceramic achieves a maximum output voltage of 2.28 V, 1.26 times higher than that of its PSZNZ 0.44 T 0.36 counterpart, and a relative voltage change rate of < 10% over 20–200 °C. These results demonstrate that the PSZNZ 0.42 T 0.38 ceramic integrates high piezoelectric performance and reliable temperature stability, making it a viable and promising candidate for ultrasonic transducers operating under high-temperature conditions.