METHOD OF GROWING MIXED COBALT-NICKEL-POTASSIUM SULPHATE CRYSTALS FOR ULTRAVIOLET RANGE OPTICAL FILTERS Russian patent published in 2015 - IPC C30B7/08 C30B29/10 

FIELD: chemistry.

SUBSTANCE: invention relates to crystallography. The method includes preparing a mother solution followed by cooling thereof in a crystalliser, inside of which an inoculating crystal is placed on a platform, wherein the method includes separately preparing cobalt sulphate, nickel sulphate and potassium sulphate solutions through dissolution thereof in hot tridistilled water, mixing said solutions to provide the ratio of potassium-cobalt sulphate K₂Co(SO₄)₂·6H₂O and potassium-nickel sulphate K₂Ni(SO₄)₂·6H₂O - KCSH/KNSH in the obtained mother solution in the range of 1:4 to 4:1, collecting part of the solution to obtain inoculating and sample crystals in a Petri dish, specifying the saturation temperature of the obtained mother solution from the change in the size of the sample crystal and then filtering the mother solution, placing the platform with the obtained inoculating crystal inside the crystalliser and heating to temperature higher than the saturation temperature by 10-15°C, heating the filtered mother solution to temperature higher than the saturation temperature by 10-15°C, pouring said mother solution into the crystalliser inside of which the inoculating crystal is located, and cooling the mother solution inside the crystalliser to temperature lower than the saturation temperature by 0.05-0.1°C, followed by controlling the temperature of the solution for 20-28 hours, and then cooling at a rate of 0.05-0.5°C/day to room temperature, or when the mother solution reaches a temperature lower than the saturation temperature by 0.05-0.1°C, turning on a mixer in reverse mode and cooling the solution to room temperature, when the solution reaches room temperature, draining the solution and retrieving the obtained crystal from the crystalliser.

EFFECT: obtaining large crystals, having high transmission in the UV range.

3 cl, 3 dwg, 1 tbl