Preparation method of cerium-doped lanthanum chlorobromide scintillating crystal

Abstract

The invention discloses a preparation method of a cerium-doped lanthanum chlorobromide scintillating crystal. The crystal is a solid solution crystal with excellent scintillating performance; and the molecular formula of the crystal is CexLal-xClyBr3-y, wherein x is more than 0 and less than 1; y is more than 0 and less than 3. In the method disclosed by the invention, a related halide crystalline hydrate with low cost is used as an initial raw material to be dissolved in water and react with SOCl2 and water to obtain a high-purity CexLal-xClyBr3-y polycrystalline raw material with even components at the room temperature; and then the polycrystalline is used as the raw material for growing of a CexLal-xClyBr3-y single crystal by using a crucible descending method. The method can be used for obtaining the CexLal-xClyBr3-y scintillating crystal with even components at a lower cost.

Description

technical field [0001] The invention relates to a preparation method of cerium-doped lanthanum chloride bromide scintillation crystal, the chemical composition of the scintillation crystal is Ce x La 1-x Cl y Br 3-y , wherein 0<x<1, 0<y<3, specifically relates to the pretreatment of starting raw materials and crystal growth by crucible descent method, and belongs to the field of material preparation. Background technique [0002] Scintillation crystals can distinguish high-energy rays, and are widely used in nuclear radiation detection fields such as medical diagnosis (X-CT, PET, SPECT, etc.), safety inspection (container inspection, luggage inspection, etc.), oil well exploration (oil well detection probe), etc. [0003] An ideal scintillation crystal should have the characteristics of high density, high light output, fast decay, and stable physical and chemical properties, but it is difficult to have a scintillation crystal that can satisfy these characteris...

AI Technical Summary

Problems solved by technology

As far as the first method is concerned, although the crystal phases can be mixed more uniformly, the smallest particle size of the crystals is also on the order of microns, so the crystals of lanthanum chloride, lanthanum bromide, cerium chloride or cerium bromide It is still dispersed and does not dissolve each other to form a solid solution polycrystal; as for the second method, although the crystal phases have been melted at high temperature, the temperature of the molten crystal is usually only 100 ° C higher than the melting point. If the melting temperature is too high High, because the vapor pressure of each component is different, so the degree of volatilization is different, which will lead to changes in the components. In addition, because each crystal phase has a certain viscosity, the transport capacity of the components at a specific temperature is limited, so After the raw materials are melted at high temperature, it takes a long time to keep warm to achieve complete composition uniformity.

[0009] In addition, anhydrous high-purity lanthanum chloride, lanthanum bromide, cerium chloride and cerium bromide and lanthanum chloride heptahydrate LaCl with crystal water 3 ·7H 2 O, lanthanum bromide heptahydrate LaBr 3 ·7H 2 O, cerium chloride heptahydrate CeCl 3 ·7H 2 O and cerium bromide heptahydrate CeBr 3 ·7H 2 Compared with O, anhydrous lanthanum chloride, lanthanum bromide, cerium chloride and cerium bromide are extremely expensive, so the cost of raw materials for growing cerium-doped lanthanum chloride bromide solid solution single crystal is very high

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