PROCEDURE FOR PRODUCTION OF MONOCRYSTALS AND FACILITY FOR IMPLEMENTATION OF THIS PROCEDURE Russian patent published in 2012 - IPC C30B11/06 C30B29/46 

FIELD: metallurgy.

SUBSTANCE: monocrystals of binary and ternary compounds based on sulfur, selenium and tellurium are produced by means of directional solidification from the melt or solution-melt in the device, which includes two-zone furnace located vertically and comprising upper 1 and lower 2 furnaces. The melt or solution-melt 12 is placed into crucible 10, secured with rod 8 with float 7, and mounted in a sealed ampoul 5 in the bottom of which the melt of volatile component 6 is located. Upper 1 and lower 2 furnaces are separated by an air gap with transparent heat-insulating rings 3 and 4. Upper furnace 1 is sealed with mechanism 13 for moving ampoule 5. First, ampoule 5 is set with crucible 10 in the area with constant temperature of upper furnace 1 and visible lower part of rod coupling 8 in the air gap. Then the volatile component 6 evaporation temperature is set that corresponds to the vapour pressure of 100 kPa and the melt temperature in crucible 10 - at 5-10 °C below the melting temperature of the resulting monocrystal. Crucible 10 lowering speed affected by the weight increase due to dissolution of volatile component 6 in solution-melt 12 is measured and the same speed of extraction of ampoule 5 is set. The fact that the volatile component is saturated is indicated by absence of the coupling movement. Then mechanism 13 is turned off, the speed of lowering of ampoule 5 is set in accordance with the selected linear velocity of crystallisation and the process is followed until the entire melt is crystallised.

EFFECT: control of all stages of the process ensures reduction in time needed for crystal growth as well as in amount of defects.

2 cl, 2 dwg