Abstract: PMN-PT piezoelectric single crystals are widely utilized due to their outstanding performance, with varying compositions significantly impacting their properties. While the application of PMN-PT in high-power settings is rapidly evolving, material parameters are typically tested under low signal conditions (1 V), and the effects of different PT (PbTiO₃) contents on the performance of PMN-PT single crystals under high-power conditions remain unclear. This study developed a comprehensive high-power testing platform using the constant voltage method to evaluate the performance of PMN-PT single crystals with different PT contents under high-power voltage stimulation. Using crystals sized 10 mm×3 mm×1 mm as examples, this research explored changes in material parameters. The results indicate that while the trend in parameter changes under high-power excitation was consistent across different PT contents, the degree of change varied significantly. For instance, a PMN-PT single crystal with 26% PT content exhibited a 25% increase in the piezoelectric coefficient d₃₁, a 13% increase in the elastic coupling coefficient $s_11^E$, a 17% increase in the electromechanical coupling coefficient k₃₁, and a 73% decrease in the mechanical quality factor Q_m when the power reached 8 W. As the PT content increased, the PMN-PT materials became more susceptible to temperature influences, significantly reducing power tolerance and more readily reaching depolarization temperatures. This led to the loss of piezoelectric performance. Based on the findings of this study, a clearer understanding of the impact of PT content on the performance of PMN-PT single crystals under high-power applications has been established, providing reliable data to support the design of sensors or transducers using PMN-PT as the sensitive element.

Key words: piezoelectric single crystal, PMN-PT, high-power testing, constant voltage method, material parameters