Single crystals containing lead salts such as Pb(Mg1/3Nb2/3)O3 (PMN) or Pb(Nz1/3Nb2/3)O3 (PZN) and their solid solutions with PbTiO3 (PT) demonstrate superior properties for expanding ultrasonic transducer and actuator applications. However, conventional methods for growing ceramic single crystals provide slow growth rates and are not readily transferable to large scale manufacturing.
This patented invention provides a cost-effective method of fabricating single crystal ferroelectric materials suited for applications requiring complex shapes, such as 1-3 and 2-2 piezocomposites. The method comprises embedding or bonding a seed single crystal to a dense polycrystalline precursor and allowing the boundary to migrate through polycrystal under the influence of grain boundary curvature. Methods are also provided for low-cost manufacturing of single crystal ferroelectric materials and to increase the rates at which single crystals can be manufactured from polycrystalline precursors. In feasibility tests, growth distances were of the order of a few millimeters.
Conrad F. Mir
President, CEO and Director
Calmare Therapeutics Incorporated