Czochralski crystal growth of Zn2Te3O8

Crystal growth in the ZnO–TeO2 system was investigated using Czochralski technique in a 2.5 kHz induction heating system. Several runs and experiments helped optimize the Zn2Te3O8 growth process, which was limited by quite a few difficulties. These difficulties include the evaporation of TeO2 material above 700 °C, the formation of more than one phase during the growth, and the lack of a Zn2Te3O8 single crystal to initiate the growth. The main and most persisting problem is that there is no stable phase in the system that forms a line compound at which the crystal growth should be attempted. The resulting material was formed of many single crystals and a mixture of other phases. Single Zn2Te3O8 crystals of sizes ranging between 50 and 200 mm3 resulted when the pulling rate was 1.1 mm/h and the rotation speed was 12 rpm. These single crystals were extracted and their optical and electrical properties were studied for the first time. Using other pulling rates and rotation speeds returned smaller crystals with sizes ranging between 15 and 35 mm3.