Purpose of the development: The method is for growing single crystals of refractory oxides, in particular aluminum oxide, with a high optical performance and an increased life of materials of construction of the thermal unit.

Recommended application field: Grown single crystals are not restricted for use in standard optics and optoelectronics.

Technical characteristic: Grown this way mono crystal 30.170.250mm3 have the following structural and optical properties: the density of dislocations <104cm-2; rocking curve fluctuations <6 20sec; chemical purity Al2O3> 99.997% concentration of individual impurities <10rrm, Te - <4rrm; density of scattering centers size 5 microns to no more than 104cm-3.

Advantages over analogues: Application of this method allows increasing the yield of marketable products by 20% compared with the prior art. Service life of the carbon heat shields of material and items from tungsten and molybdenum is 20 thousand hours, which is 2 times higher than in the prior art. In this case the cost of materials thermal unit of the total cost of one growing up 25%. Grown single crystals are not restricted for use in standard optics and optoelectronics.

The development stage readiness: Pre-production model is made

Description of the development:
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The basis of the invention is to growing single crystals of the refractory oxides including alumina , directional solidification of the melt in the crucible and less time consuming way to obtain a crystal with a high optical performance and an increased life of materials of construction of the thermal unit . The solution of this problem is provided in that in the method of growing single crystals of aluminum oxide , comprising a preliminary evacuating to a pressure of 10 - 20Pa and directional solidification of the melt in a protective gas atmosphere , before the crystallization heat treatment is carried out of the thermal unit when the raw material , and 2030-2050 ° C for 4-5 hours under continuous pumping , and then was filled with argon to a pressure of 0.1-015 MPa and a crystallization process is performed in the hydrogen chemisorption . Compliance with the required growing medium provided by interaction of hydrogen with pairs of calcium ( chemisorption ) by heating the latter with an additional heater. A preliminary heat treatment at a given time and temperature regimes leads to decontamination and cleaning of the thermal unit , the walls of the growth chamber and raw materials, thereby ensuring a balance in the system Wednesday - thermal unit, raw materials. In these conditions, as shown by the experiments , provided effective removal of reaction products (for cleaning of raw materials ) and desorption ( degassing thermal unit ) , which improves the optical quality of the grown single crystals .

Information about newness of the development:
there are inventor's certificate -- 1 items

corresponds technical description
Ready for implementation

Possibility of transfer abroad:
Licence's sale
Technological document's sale
Combinated reduction to industrial level
Creation of joint enterprise
Realization of finished commodity
Joint production, sale, exploitation

Photo

Country Ukraine

For additional information turn to:
E-mail: gal@uintei.kiev.ua