METHOD OF PRODUCTION OF SCINTILLATION MONOCRYSTALLINE LUTECIUM-YTTRIC ALUMINATE Russian patent published in 2004 - IPC

FIELD: production of chips.

SUBSTANCE: the invention presents a method of production of crystals, in particular it is dealt with production of monocrystals of lutecium - yttric aluminate and may be used at production of the scintillation elements used in detectors of ionizing radiations in medical troubleshooting instrumentation. The method of production of a monocrystal of lutecium - yttric aluminate, activated with admixture of Се by Chokhralsky method, provides for growing up a monocrystal by its drawing from the charge melt containing Al ₂ O ₃ aluminum oxide_{as inoculumfrom iridic crucibles at the temperature of the melt from 1900 up to 2000°С, and the rate of the inoculum drawing out of the melt of 0.1 up to 8.0 mm / h, the rate of its rotation - from 2.5 up to 30 minutes^-1 and the rates of the monocrystal cooling after the end of the growing process - from 50 up to 500° С/h. At that as the inoculum they use a monocrystal of aluminate of yttrium or a monocrystal of aluminate of yttrium with the content of admixture of the rare-earth ions of no more than 1 mass percent. The initial charge is added with oxide of lutecium Lu2O3 and oxide of yttriumY2O3 in a molar ratio from 1 up to 20 and with the molar ratio of their total content with the above mentioned aluminum oxide Al2O3 from 0.95 up to 1.05 of a stoichiometry and admixture of ceric oxide CeO2, in the amount providing in an off-the shelf crystal the share of Се from 0.01 up to 0.9 mass percents. The growing is conducted in a gaseous medium composed of the noble gases with a share of oxygen - in the limits from 10^-6 up to 1 volumetric percent. The offered method provides substantial improvement of the optical properties of the crystals and an increase of their light output.}

EFFECT: method provides substantial improvement of the optical properties of the crystals and an increase of their light output.

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