Purpose. Bi4Ge3O12 single crystals are used to produce sensitive elements for ionizing radiation detection devices.
Technical properties. The technology for producing bismuth germanate scintillation single crystals allows: – to produce bismuth germanate scintillation single crystals weighing up to 90% of the original raw material weight; – to produce bismuth germanate scintillation single crystals that are not inferior in characteristics to foreign analogues; – to significantly extend the service life of process equipment.
Scope. Growing single crystals, instrument making.
Advantages. The technology allows using up to 90% of the melt to grow a single crystal, which significantly reduces the cost price. Also, the use of this technology significantly reduces the number of bubbles in the single-crystal bubble, which improves the properties of the single crystal.
Technical and economic effect. The implementation of the technology will allow using up to 90% of the melt for growing single crystals, which will significantly reduce the cost of the final product, and will also contribute to the creation of additional jobs.
Description. The technological process for producing Bi4Ge3O12 single crystals consists of preparing crucibles, synthesizing the batch, cladding the crucibles, growing the single crystal using the Czochralski method on the nucleus, and annealing the single crystal. First, a heating unit is assembled to clean the crucible from the remains of the raw material. The heating crucible, located inside the heating unit with the bottom up, to the melting point of Bi4Ge3O12, so that the melt residues flow out of the crucible. The crucible is cooled to room temperature. The bismuth germanate batch is prepared by mixing bismuth and germanium oxides in a stoichiometric composition and annealing the mixture in a KS-520 furnace at a temperature of 80-85% of the melting point of the bismuth germanate. Six bismuth germanates are filled into a bunker, coaxially located above the crucible in the thermal unit of the OXID single crystal growth plant. The bunker is heated to the melting temperature of the bismuth germanate, and during melting the molten batch flows to the crucible. After filling the crucible, the bunker is cooled.