REFRACTORY OXIDE MONOCRYSTALS GROWING METHOD Russian patent published in 2008 - IPC C30B11/02 C30B11/14 C30B29/20 C30B29/28 

FIELD: processes for high-temperature crystallization from melts, possibly growing of super-large mono-crystals of refractory oxides.

SUBSTANCE: method for growing refractory oxide mono-crystals by directional horizontal crystallization comprises steps of creating in vacuum chamber by means of heating devices temperature field; melting in created field initial crystallized material placed in container being open upwards reservoir in the form narrowed at one side parallelepiped shaped boat; forming crystal from oriented mono-crystalline seed arranged in narrowed part of container and made of material corresponding to grown crystal due to moving container with melt charge in gradient temperature field. At growing process, crystallization speed is controlled in axial, radial and vertical directions by regulating relations of heat flux values of heating devices irradiation, namely heat flux of radiant energy incident to melt heel surface and conductive heat flux passing through lateral walls and bottom of container. Desired temperature gradients of temperature field along interface of melt material phases and grown crystal - crystallization front are provided due to setting difference between temperature of phase interface and equilibrium melting temperature equal to 15 - 25°C. Inclination angle of crystallization front relative to plane of container bottom at forming vertical temperature gradient is set in range 55 -90°. Width of seed is selected in range 3 - 5 mm; enlargement angle of mono-crystal is set in range 100 - 140°; values of enlargement arms of mono-crystal are selected up to 300 mm. Invention provides increased useful surface area (rectangular portion) of grown crystals by 30 - 45% and flat crystallization front in zones of lateral corrugations of container.

EFFECT: minimized possibility of occurring stresses, complete elimination of block formation in grown crystal.

5 cl, 1 tbl, 2 dwg