Growth of the high quality and large size paratellurite single crystals

A new method was used to prepare the TeO2 powders with high purity. Acousto-optic paratellurite (TeO2) crystals were grown by the modified Bridgman method using the high purity TeO2 powders. The highly perfect TeO2 single crystal (bubble-free, twin-free, and crack-free) up to 52×52×80 mm3 was obtained. The crack reason of the single crystal was discussed. The optimum conditions of growing high quality and large size TeO2 single crystals were obtained, which included a growth rate of less than 0.6 mm/h, a temperature gradient in solid-liquid interface of about 45 K/cm and a growth direction of 〈1 1 0〉.