New Material Compositions That Expand the Operating Domain of Piezoelectric Single Crystals

High-drive applications for new PMN-PT piezoelectric crystals require additional bias fields due to the relatively low coercivity (EC, ~ 2 kV/cm). However, this complicates the design of Navy devices, increases the cost, and makes the devices more susceptible to electrical failure. Thus, the goals of the proposed project are to increase EC, and extend the thermal stability of PMN-PT based transducers through compositional modifications (e.g., additions of lead indium niobate). We propose a budget of $749,908 for the growth and commercialization of PIN-PMN-PT transducer crystals, 3 inch in diameter, over a 2-year period. We will subcontract to the University of Illinois at Urbana-Champaign to support work for an understanding of the role of composition and structure on domain pinning and increased coercivity. We anticipate establishing manufacturing methods for the growth of PIN-PMN-PT based crystals with high EC (3x) and improved thermal stability (i.e., with de-poling temperature above 110 °C). In addition, the piezoelectric, dielectric and elastic properties of the grown crystals will be systematically characterized to provide guidelines for their use in Navy transducer systems, and commercial ultrasound devices.