Rare-earth calcium oxyborate crystals, ReCa4O(BO3)3 (ReCOB, Re = Er, Y, Gd, Sm, Nd, Pr, and La), are potential piezoelectric materials for ultrahigh temperature sensor applications, due to their high electrical resistivity at elevated temperature, high piezoelectric sensitivity and temperature stability. In this paper, different techniques for ReCOB single-crystal growth are introduced, including the Bridgman and Czochralski pulling methods. Crystal orientations and the relationships between the crystallographic and physical axes of the monoclinic ReCOB crystals are discussed. The procedures for dielectric, elastic, electromechanical and piezoelectric property characterization, taking advantage of the impedance method, are presented. In addition, the maximum piezoelectric coefficients for different piezoelectric vibration modes are explored, and the optimized crystal cuts free of piezoelectric cross-talk are obtained by rotation calculations.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Science(all)
- Condensed Matter Physics
- Inorganic Chemistry