Single Crystal Growth of Relaxor Based Piezoelectric Materials for High Performance Transducers

Period of Performance: 01/21/1999 - 01/20/2001


Phase 2 SBIR

Recipient Firm

TRS Ceramics, Inc.
2820 East College Avenue
State College, PA 16801
Principal Investigator

Research Topics


Single crystals of the relaxor ferroelectric PMN:PT combine high piezoelectric activity (strains > 1 %), high electromechanical coupling (k33 > 90 %), and low dielectric loss. This Phase II program will focus on the growth of large- area (1-4 cm diameter) PMN:PT single crystals using the Bridgman-Stockbarger method with the goal of producing crystals that meet the size requirements for DOD acoustic transducer and electromechanical actuator applications. In Phase I, an optimum composition in the PMN:PT system was selected and dopant modification studies were begun. Bridgman growth runs were also performed, resulting in a 2-inch diameter perovskite crystal ingot. In Phase II, Bridgman growth experiments will continue in order to optimize crystal size and quality, and a custom furnace will be designed and constructed. A comprehensive study of the piezoelectric and dielectric properties as a function of composition will also be undertaken, with a focus on increased coercive field and dielectric maximum temperature. In addition, TRS will prepare several single crystal prototype devices according to sponsor specifications including multilayer actuators and Navy transducers. TRS Ceramics, Inc. has an exclusive license from the Pennsylvania State University for the commercial application of these single crystals in actuators and biomedical transducers.