METHOD OF GROWING INFRARED MONOCRYSTALS BASED ON SOLID SOLUTIONS OF TlBrI - AgCl SYSTEM (VERSIONS) Russian patent published in 2024 - IPC C30B11/02 C30B29/12 C30B33/02 

FIELD: growing optical monocrystals.

SUBSTANCE: invention relates to growing optical monocrystals and can be used in making flexible polycrystalline infrared light guides. High-purity homogeneous single-phase mixture with purity of cationic impurities 0.1 ppm for growing infrared monocrystals based on solid solutions of the TlBr_0.46I_0.54 – AgCl system is obtained by hydrochemical method of thermal zone crystallisation-synthesis with double recrystallisation. Mixture is then loaded into an ampoule made from Pyrex glass, which is placed into an apparatus for growing monocrystals using the vertical Bridgman method, melted and the melt is instilled into a growth ampoule, also made from Pyrex glass. After that, holding for two hours at the same temperature and moving the ampoules into the lower zone of the installation, annealing is carried out at temperature of 100 °C in the same installation for ten hours to form monocrystals of cubic system of NaCl structure type. According to the first version, a charge containing, mol. %: solid solution of TlBr_0.46I_0.54 – 90.0–98.0; silver chloride – 10.0–2.0. Melting in the ampoule is carried out at temperature of 430 °C, and its movement to the lower zone of the installation is carried out at temperature of 160-180 °C at rate of 0.5–0.8 mm/h. According to the second version, a charge containing, mol.%: silver chloride – 80.0–95.0; solid solution of TlBr_0.46I_0.54 – 20.0–5.0. Melting in the ampoule is carried out at temperature of 470 °C, and its movement to the lower zone of the installation is carried out at temperature of 155–200 °C at rate of 0.5–1.0 mm/h.

EFFECT: obtained monocrystals are radiation-resistant, insoluble in water, plastic and transparent in range from 0.4 to 55 mcm in the infrared region; polycrystalline flexible infrared light guides with a bend radius of up to 50 mm, made from these monocrystals by extrusion, are not destructed over time as a result of recrystallisation of grains.

2 cl, 1 dwg, 6 ex