GROWTH METHOD OF PARATELLURITE CRYSTALS OF POLYGONAL SHAPE, AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2014 - IPC C30B15/00 C30B15/14 C30B15/22 C30B29/16 

FIELD: metallurgy.

SUBSTANCE: growth method of paratellurite crystals of a polygonal shape from a melt involves build-up of tellurium dioxide powder into a platinum melting pot; creation of the required axial temperature distribution, which is provided by a temperature gradient of 1-2 degrees/cm above the melt, with a step of 2-3 degrees at an air-melt boundary line, by temperature increase by 2-3 degrees to the depth of 2 cm and temperature constancy throughout the rest melt thickness; determination of equilibrium temperature when an inoculating crystal touches the melt surface; growth of the crystal at its rotation and drawing with the specified change of the cross-sectional area using a weight automatic control system and a heating surface with four independent heating elements in a vertical direction, separation of the crystal from the melt and cooling of the crystal till room temperature; with that, a furnace is used, in which middle heating elements are made in the form of three equal segments of 120 degrees each, and growth of the crystal is performed under conditions of non-homogeneous radial warm-up of the melt by temperature increase by 1-2 degrees in a 120-degree sector in the lower part of the growth melting pot.

EFFECT: invention allows obtaining large-sized paratellurite crystals with decreased light scattering and fully free from gaseous inclusions.

2 cl, 4 dwg, 1 tbl, 1 ex