Stoichiometric LiTaO3 single crystal growth by double crucible Czochralski method using automatic powder supply system

Stoichiometric LiTaO3 single crystals, 45 mm in diameter and 50-85 mm in length, were grown by the double crucible Czochralski method equipped with automatic powder supply system using radio-frequency heating and automatic diameter control system. The crystals were grown from an off-congruent Li-rich melt (Li2O 58-59 mol%) in the inner crucible made of Ir, and the stoichiometric powder was supplied smoothly and continuously to the outer melt at the rate of weight increase of the growing crystal as monitored by a load cell. The chemical composition of the crystal was confirmed by the Curie temperature measurements to be nearly stoichiometric (Li2O 49.9 mol%). (C) 1999 Elsevier Science B.V. All rights reserved.