PbTiO_3/Pb(Zr,Ti)O_3 sol-gel composite for ultrasonic transducer applications

摘要

A new sol-gel composite material, PbTiO_3 (PT)/Pb(Zr,Ti)O_3 (PZT) was developed for ultrasonic transducer applications, especially for high temperature applications, since long-term monitoring is desired for safety assurance. PT was considered as a good piezoelectric powder candidate because of its reasonable piezoelectric constant, high Curie temperature of approximately 760 K, and low dielectric constant. Approximately 50-μm-thick PT/PZT, PZT/PZT, Bi_4T_3O_(12) (BiT)/PZT, and CaBi_4Ti_4O_(15) (CBT)/PZT films were fabricated on 3-mm-thick titanium substrates and their ultrasonic performances were compared at various temperatures. As a result, PT/PZT poled at 470 and 670 K showed higher sensitivity than PZT/PZT, BiT/PZT and CBT/PZT from room temperature to 630 K. Since PT/PZT showed stable thermal cycle results from room temperature to 630 K, PT/PZT could be a good piezoelectric material for ultrasonic transducer application, not only for high temperatures but also a wide temperature range.