Growth and Characterization of Lanthanum Calcium Oxoborate LaCa₄O(BO₃)₃Single Crystals

Abstract

Lanthanum calcium oxoborate LaCa4O(BO3)3 (LaCOB) bulk single crystals were grown by the Czochralski technique. The crystals have almost constant transmittances between 320 and 2500 nm. The relationship between the growth habit and crystallographic abc - rectangular XYZ axes was clarified. Some dielectric and piezoelectric constants as well as elastic compliance constants of the LaCOB crystals were evaluated. The surface acoustic wave (SAW) and pseudo-SAW (PSAW) parameters of the LaCOB crystals were also measured. For the SAW, the largest electromechanical coupling coefficient of approximately 0.26% and a velocity of 3550 m/s were obtained for the YX orientation. For the PSAW, these parameters were approximately 0.6% and 4000 m/s for the ZY orientation.