NUMERICAL AND EXPERIMENTAL STUDIES ON CRACK FORMATION IN LINBO3 SINGLE-CRYSTAL

A global analysis of heat transfer was carried out in an inductively h eated Czochralski (CZ) furnace which was actually used to grow LiNbO3 single crystals, and then the temperature profiles obtained were used to calculate the three-dimensional thermal stress field in the crystal . By comparing the numerical results with the experimental ones, it wa s found that controlling the thermal environment in the CZ furnace so that the thermal stresses at the crystal surface might not exceed a ce rtain value is important to realize the cracking free growth operation . In this study, this was accomplished through some modifications in t he furnace design such as insertion of an after-heater into the furnac e. These findings were verified by additional numerical simulations an d crystal growth experiments for some growth conditions.