Single crystal relaxor ferroelectric lead magnesium niobate- lead titanate (PMN-PT) solid solution doped with Ba or La to modify the dielectric and electromechanical properties is emerging as a material of choice in both Naval and commercial applications to replace similar ceramic compositions in electrostrictive actuators, high power sonar projectors and piezoelectric transducers for high resolution, high sensitivity medical ultrasound imaging. Single crystals, in contrast to ceramics exhibit broadband response, a k33 electromechanical coupling coefficient >90% and a strain >1% is possible. This work will focus on refinement of a top-seeded solution growth (TSSG) technique for producing single crystals. Design of experiments methodology will be applied. Compositions for electrostrictive or piezoelectric response of the doped PMN-PT family materials will be grown by the same method. TSSG has greater potential than sealed crucible flux growth techniques for producing high quality inclusion-free crystals in high yield. Basic aspects of the process, seeding and control of secondary nucleation during growth are executed under visual observation. During growth and cool-down, the crystal is unconfined and not subject to external potentially damaging stress. The TSSG method has potential for cost effective scale-up.
