GROWTH OF ZNTE CRYSTALS BY THE HEAT EXCHANGER METHOD (HEM)

ZNTE IS A DIRECT BANDGAP MATERIAL WITH AN ENERGY GAP OF 2.25 EV AND MELTING POINT OF 1298 DEGREES CENTIGRADE. THIS MELT TEMPERATURE IS CLOSE TO THE SOFTENING TEMPERATURE OF BETA SILICA AMPOULES; THEREFORE, ATTEMPTS HAVE BEEN MADE TO PREPARE ZNTE FROM SOLUTION. THE PROJECT IS ADAPTING THE HEAT EXCHANGER METHOD (HEM) FOR THE GROWTH OF ZNTE CRYSTALS. THE INTEGRITY OF THE SILICA AMPOULE CAN BE MAINTAINED DURING HEM GROWTH BECAUSE THERE ARE NO TEMPERATURE GRADIENTS BUILT INTO THE HEAT ZONE AND A SUPPORT STRUCTURE FOR THE AMPOULE CAN BE USED WITH MINIMAL INTERFERENCE FOR HEAT FLOW. IT IS INTENDED TO GROW CRYSTALS UNDER LOW SUPERHEAT CONDITIONS AND TO CONTROL THE TEMPERATURE GRADIENT IN THE SOLID BY THE HEAT EXCHANGER. IF MAINTAINING THE INTEGRITY OF THE SILICA AMPOULE BECOMES A PROBLEM, IT IS INTENDED TO CARRY OUT GROWTH EXPERIMENTS IN OPEN SILICA OR GRAPHITE CRUCIBLES WITH AN INERT GAS OVER-PRESSURE.