Codoping modified lithium gadolinium borate scintillation crystal and preparation method thereof

Abstract

The invention belongs to the field of scintillation crystal materials, especially relating to a codoping modified lithium gadolinium borate scintillation crystal and a preparation method thereof. The codoping modified lithium gadolinium borate scintillation crystal has the following chemical formula: Li6CexNyGd1-x-yB3O9-delta/2Mdelta, wherein, M is selected from one or two elements of F, Cl, Br and I, N is selected from one or two elements of Sc, Y, La and Lu, and at least one of Li element, Gd element and B element exists in the form of special isotope; x is more than 0 and is 0.2 at most, y is 0 at least and is smaller than 1, delta is 0 at least and 0.1 at most, and y and delta can not be 0 at the same time. The preparation method comprises the following steps: raw materials are mixed, synthesized in solid phase and transformed to grow and prepare single crystal form with a pulling method in a single crystal growing furnace. The codoping modified lithium gadolinium borate scintillation crystal of the invention takes Ce ion as an luminous center, and lithium, gadolinium and borate elements exist in one or the combination of Li-6, gadolinium-155, gadolinium-157 or borate-10 isotope so as to perform the function of generating nuclear reaction with the detected neutrons.

Description

technical field [0001] The invention belongs to the field of scintillation crystal materials, in particular to a co-doped modified lithium gadolinium borate scintillation crystal and a preparation method thereof. Background technique [0002] As a functional material that emits light through high-energy particle or ray excitation, scintillation crystals are very sensitive to the microscopic defects of the crystals. The scintillation properties of the crystals can be improved by changing the defect state of the crystals by doping, thereby forming new functional crystals. Material. Ce-doped lithium gadolinium borate crystals (Li 6 Ce x Gd 1-x B 3 o 9 ) detects neutrons by reacting the enriched lithium-6 or boron-10 or gadolinium-155 or gadolinium-157 isotopes in the crystal with neutrons, first reported by J.B.Czirr of the United States in 1996 as neutron detection scintillation Potential uses of crystals. As a new neutron detection scintillation crystal, Li 6 Ce x Gd...

AI Technical Summary

Problems solved by technology

Generally, the valence state change of cerium ions is controlled by controlling the growth atmosphere, but its mechanism and effect are difficult to be effectively controlled.

This is also the case for almost all doped Ce 3+ The problem exists in the scintillation crystals of ions, which makes the luminous uniformity of the crystals grown in different parts and different furnaces is very poor.

[0010] (2) Li 6 Ce x Gd 1-x B 3 o 9 The crystal is a kind of borate crystal, which has poor thermal conductivity, and its melt contains a large number of borate groups, which is easy to form a network structure, resulting in high melt viscosity and slow growth rate. The influence of crystal growth is large, making the crystal growth difficult to control

In addition, the crystal also has multiple cleavage planes such as (010), (121) and (012), which make the crystal easy to crack and difficult to process wafers with a diameter larger than 30 mm, which limits the research and application of the crystal.

[0011] (3) Li 6 Ce x Gd 1-x B 3 o 9 Crystals contain a lot of 155 Gd and 157 Gd isotope, its cross section for reacting with neutrons is much larger than 6 Li and 10 B isotopes, which affect neutrons and 6 Li or 10 The B isotope reacts, reducing the crystal utilization 6 Li or 10 Efficiency of B isotopes for neutron detection

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