Growth of TeO2 single crystals by the low temperature gradient Czochralski method with nonuniform heating

• Local overheating in Czochralski furnace was created.
• Bubble-free TeO2 crystals were grown.
• Improvement of quality is a result of decomposition of melt clusters.

A growth station for growing paratellurite single crystals is presented. Modification of Czochralski furnace consists of nonuniform heating of melt by remaining low temperature gradients near the front of crystallization. It is supposed that local overheating of the lower parts of the melt breaks particle associates in the melt. This assumption is confirmed by the growth of bubble-free TeO2 crystals weighting up to 1.8 kg.