Lanthanum, dysprosium and cerium co-doped lutetium-yttrium orthosilicate scintillating material and crystal growth method

Abstract

The invention discloses a lanthanum, dysprosium and cerium co-doped lutetium-yttrium orthosilicate scintillating material and a crystal growth method of the lanthanum, dysprosium and cerium co-doped lutetium-yttrium orthosilicate scintillating material. The chemical formula of the scintillating crystal is La2pDy2qCe2m(Lu(1-n)Yn)2(1-p-q-m)SiO5, wherein p is more than 0 and less than or equal to 0.02, q is more than 0 and less than or equal to 0.02, m is more than 0 and less than or equal to 0.03, n is more than or equal to 0.01 and less than or equal to 0.1, p, q and m meet the condition that pplus q plus m is more than 0 and less than or equal to 0.05; the growth method is as follows: S1: synthesizing a poly-crystal material block at the solid phase at the high temperature; S2: compressing and fusing the poly-crystal at the atmosphere of the protective gas; and S3: growing at equal diameter, and using a PID algorithm to automatically cool and anneal. The Dy and the La are doped in LYSO, the vacancy for growing the crystal is increased, the excessive oxidation of the crystal is avoided, the scintillating performance of the crystal is guaranteed, the luminescence spectrum of the crystal is expanded, and the case substitution rates of the ions Lu and Y are increased by means of cold isostaitc pressing, the automatic temperature-controlled growth is implemented through the PID algorithm, and the consistency of the crystals growing in batches is guaranteed.

Description

technical field [0001] The invention relates to the technical field of scintillation materials and crystal growth, in particular to a yttrium lutetium silicate scintillation material co-doped with lanthanum, dysprosium and cerium and a crystal growth method thereof. Background technique [0002] Yttrium lutetium silicate scintillation crystal is a new type of scintillation crystal that appeared in the past 10 years. It is widely used in various radioactive detection fields due to its high light output, fast luminescence decay, high effective atomic number and high density. At present, the only units capable of producing yttrium lutetium silicate scintillation crystals in China are Shanghai Institute of Silicon, CLP 26 and Beijing Glass Research Institute, and the product supply is far below the domestic market demand. The yield of the yttrium lutetium silicate crystal grown in the prior art is low, mainly due to three reasons: (1) in the process of preparing the yttrium lute...

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Problems solved by technology

The yield of yttrium lutetium silicate crystal grown by the prior art is low, mainly because of three reasons: (1) in the process of preparing yttrium lutetium silicate growth raw material, it is easy to introduce impurities to reduce the segregation coefficient and doping concentration of doping ions, Leading to unqualified optical quality; (2) In the growth process of yttrium lutetium silicate, relying on manual intervention to control the growth, the difficulty coefficient of annealing and cooling is high, it is easy to cause crystal cracking, and the repeatability is poor, which is not conducive to the consistency of growth batches , it is difficult to meet the large-scale production; (3) In order to improve the luminous intensity of yttrium lutetium silicate, it is necessary to carry out high-temperature oxygen diffusion on the crystal to make up for the oxygen defects in the crystal lattice, and excessive oxidation will occur, resulting in the luminescence center Ce 3+ Oxidized to Ce 4+ , resulting in weak light transmittance at 420nm and reduced scintillation performance

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