Development of hot-zone structure for LiTaO3 single crystal growth by simulation

Lithium tantalate (LiTaO3) crystal is widely used in infrared detection, acoustic surface wave devices and optical applications due to its outstanding piezoelectric, pyroelectric, and nonlinear optical properties. Over the past few decades, LiTaO3 single crystals have been studied intensively for their excellent acoustic and electro-optical properties. Today, most of LiTaO3 single crystals are made by czochralski methods, which is well-defined growing methods for high quality single crystal. To grow LiTaO3 single crystal in optimized condition, hot-zone structure should be designed properly. Temperature gradient, melt flow and heat dissipation should be optimized by managing the hot-zone structure. Especially, minimizing the heat dissipation and temperature gradient play a key role deciding the quality of grown single crystal. <br/><br/> In this study, we designed hot-zone structure in czochralski furnace for LiTaO3 single crystal growth. We added ring parts above the iridium crucible in which LiTaO3 crystal grow. It reduced heat dissipation and temperature gradient inside the hot-zone through bothering heat flow toward upper side of the system. Vertical and horizontal temperature gradient in whole range position was analyzed. Optimized size and position of ring parts were designed. For the simulation of this system, CGSim SW was used. We expect that our research results would contribute to the development of LiTaO3 single crystal growing technology.