METHOD OF PRODUCING LUMINESCENT OXIDE COMPOSITION FOR RADIATION CONVERTER IN WHITE LIGHT SOURCES Russian patent published in 2024 - IPC C09K11/78 C09K11/80 C04B35/44 C04B35/505 F21V9/30 F21Y115/10 

FIELD: chemical industry.

SUBSTANCE: invention can be used in making super-bright laser-excited white light sources. When producing a luminescent oxide composition intended for a radiation converter in white light sources, chlorides or nitrates of aluminum, yttrium and cerium taken in calculated concentrations are used as initial substances. Further, the powder is co-precipitated from the prepared mother solution by adding ammonia solution thereto with continuous stirring. Obtained powder is washed, dried at 60 °C and sieved through a sieve with mesh size of 100 mcm. Annealing is carried out in stages: first in air at 700 °C with holding for 2 hours, then at 900 °C with holding for 2 hours, and then at 1,150±50 °C in medium containing 95 or 97 vol.% of nitrogen and 5 or 3 vol.% of hydrogen. Annealed product is ground in a planetary mill with addition of isopropyl alcohol as a grinding medium and 0.5 wt.% of tetraethoxysilane as a sintering additive, dried at 60 °C and sieved through a sieve with mesh size of 100 mcm. Powder is then pressed into compacts which are sintered in vacuum at temperatures of not less than 1,500 °C and not more than 1,800 °C with holding for 10 hours. Composition of the obtained ceramics consists of an aluminum oxide phase with a weight fraction of not more than 20 wt.% and phase of yttrium-aluminum garnet doped with cerium cations (YAG:Ce) is described by formula: Y_(3−x−y)Ce_(y)Al_(5+x)O₁₂, where 0.005<(x)<0.5; 0<(y)<0.1. Cerium cations are uniformly distributed over grains of the YAG:Ce phase. Luminescence maximum is in region of 545–560 nm when excited by laser radiation with wavelength of order of 450 nm. Thermal conductivity of the obtained ceramics is not less than 8.5 W/mK. No special equipment is required to implement said method.

EFFECT: disclosed is a method of producing a luminescent oxide composition for a radiation converter in white light sources.

1 cl, 3 ex