METHOD OF PRODUCING OPTICALLY TRANSPARENT GARNET MONOCRYSTALS Russian patent published in 2015 - IPC C30B15/04 C30B15/08 C30B29/28 C30B33/02 G02F1/09 

FIELD: physics.

SUBSTANCE: garnet monocrystals are obtained using a Czochralski method by melting a starting mixture, which includes a calcium-containing additive in the form of calcium oxide or carbonate, and growing a monocrystal from the melt on an oriented seed crystal with diameter of 2-8 mm with a crystal rotational speed of 2-10 rpm, followed by annealing in a hydrogen atmosphere at 850-950°C for about 5 hours until the orange colour disappears, wherein crystal pulling on the oriented seed crystal is carried out at a rate of 0.5-2 mm/h, and the starting mixture used is a mixture of terbium, scandium and aluminium oxides, with the following ratio of components, wt %: terbium oxide - 65.85-66.98, aluminium oxide - 17.96-23.14, scandium oxide - 9.88-16.19. After growing, the crystal is annealed in a hydrogen atmosphere at 850-950°C for about 5 hours until the orange colour disappears. The obtained monocrystals are used to make magnetooptic elements with a diameter of more than 30 mm with an absorption coefficient of 0.8·10^-3 cm^-1, Verdet constant of 46-48 rad/(m·T) at wavelength of 1064 nm, medium breakdown threshold of not less than 5 J/cm² at 10 Hz at wavelength of 1064 nm.

EFFECT: invention enables to obtain optically transparent colourless garnet monocrystals.

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