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Information × Registration Number 0302U001511, 0101U003493 , R & D reports Title Investigation of a complex effect of anionic vacancies and foreign phase impurities on optical characteristics of crystals grown in gas medium; development of scientific foundations for the preparation of large optical elements of sapphire for operation under the extreme conditions popup.stage_title Дослідження впливу домішок на оптичні характеристики сапфіра Head Dan'ko O.Ya., Registration Date 12-03-2002 Organization Department of Optical and Constructional Crystals of STC <Institute for Single Crystals> popup.description2 Mechanisms of deep purification of alumina in the process of its secondary melting in the reducing gas atmosphere under conditions of intensive convection of melt have been investigated. Perspectives of such method for growing high optical quality crystals is shown. Critical concentrations of the reducing components (CO, H2) in the gas atmosphere have been determined. A method of lowering their concentration down to optimal ones at which possible is growth of high optical quality crystals has been worked out. Decrease of the velocity of evaporation and dissociation of melt under these conditions allowed to prolong significantly the service time of constructional materials of the thermal zone and to make higher the efficiency of growing sapphire crystals by horizontally oriented crystallization method.5635 Product Description popup.authors popup.nrat_date 2020-04-02 Close