Method for growing Ce<3+> doped lutetium yttrium silicate scintillation crystal

A technology of yttrium lutetium silicate and crystal is applied in the field of pulling Ce3+ doped yttrium lutetium silicate crystal, which can solve the problems of easy cracking, low crystal yield, greatly increased success rate, etc. The effect of yellowing, good crystal quality and high yield

Active Publication Date: 2014-06-11
SHANGHAI ADVANCED SILICON TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention intends to aim at the problem of oxygen content control on the basis of the prior art, especially using a specially improved crystal furnace, which can carry out high-temperature oxygen diffusion in the early stage of crystal growth, supplement oxygen content, and reduce oxygen defects; in the later stage of crystal growth Filling reducing gas or neutral gas to reduce the crystal can effectively balance the oxygen content, obtain high-quality LYSO crystal, and the success rate is greatly increased. At present, the important problem of domestic LYSO crystal is that the crystal yield is not high and it is easy to crack.

Method used

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  • Method for growing Ce&lt;3+&gt; doped lutetium yttrium silicate scintillation crystal
  • Method for growing Ce&lt;3+&gt; doped lutetium yttrium silicate scintillation crystal
  • Method for growing Ce&lt;3+&gt; doped lutetium yttrium silicate scintillation crystal

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Embodiment 1

[0028] Example 1.Ce 3+ The growth of doped yttrium lutetium silicate crystals, the specific process is as follows figure 1 Shown:

[0029] (1) Weighing and mixing: according to trivalent Ce 3+ Chemical formula Ce of doped yttrium lutetium silicate single crystal 2x (Lu 1-y Y y ) 2(1-x) SiO 5 , wherein, 0.001≤x≤0.05, 02 O and CO 2 , by oxide (Lu 2 o 3 , Y 2 o 3 , CeO 2 , SiO 2 ) The corresponding molar ratio is accurately weighed, and fully mixed into a uniform powder;

[0030] (2) Pressing and sintering: Press the mixed powder into a cylindrical cake under a pressure of 150Mpa, and sinter at 1300°C for 15 hours to form Ce 3+ Doped yttrium lutetium silicate polycrystalline cake material, in which the cold isostatic pressing machine is used for pressing, and the muffle furnace is used for sintering;

[0031] (3) Heating and melting: Put a crucible that can withstand high temperature and will not deteriorate rapidly in an oxygen environment, such as an iridium cru...

Embodiment 2

[0038] Growth Ce described in Example 1 3+ The growth furnace used for doping yttrium lutetium silicate crystals is an improved crystal furnace. The improvement of the crystal furnace was previously submitted in the application titled "A Straightening White Gem Single Crystal Growth Furnace Structure Improvement and Method" (Application No. 201210099937. On the basis of X), the main improvements are the following two aspects:

[0039] ① A gas outlet 8 is added to the heat insulator. The position of the gas outlet 8 on the heat insulator 1 is symmetrical to the left opening 4 of the gas inlet. It is mainly used for in-situ annealing after crystal growth. 2 and N 2 The mixed gas is discharged to H 2 and N 2 in the collection box;

[0040] ② On the middle opening 5 directly above the heat insulator, place a sealing cover 6 and two small doors 7 are arranged on both sides of the sealing cover, during the crystal growth process O 2 and N 2 The mixed gas flows out from here (c...

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Abstract

The invention relates to a method for growing a Ce<3+> doped lutetium yttrium silicate scintillation crystal. The method is characterized by comprising the concrete steps of (1) weighing and mixing; (2) pressing and sintering; (3) heating for fusing; (4) seeding; (5) high temperature oxygen diffusion; (6) necking, shoulder extending and keeping constant-diameter; (7) cooling; (8) in-situ annealing. According to the invention, a crystal growth furnace is properly modified, so that high-temperature oxygen diffusion and in-situ annealing at a reducing atmosphere can be simultaneously realized, oxygen balance can also be realized, and furthermore, the crystal is not easy to crack and become yellow and the good crystal quality is kept. The success rate for growing the crystal is increased from 40-45% to 75-85%.

Description

technical field [0001] The invention relates to a kind of pulling method to draw Ce 3+ A process method for doping yttrium lutetium silicate crystal belongs to the technical field of crystal growth and electronic control. Background technique [0002] Inorganic scintillation crystals are widely used in various radiation detection fields, such as nuclear medicine, nuclear physics, safety inspection, Extreme condition applications and industrial non-destructive testing, etc. The material system mainly includes Bi 4 Ge 3 o 12 (BGO), PbWO 4 (PWO), CsI(TI), NaI(TI), BaF 2 、Lu 2 SiO 5 (LSO) and yttrium lutetium silicate (LYSO), etc. [0003] Yttrium lutetium silicate (LYSO) scintillation crystal is considered to be the inorganic scintillation crystal material with the best comprehensive performance. Its effective atomic number is 64, its density is 7.1g / cm3, and its light output can reach 38000Mev. Its light output is BGO single crystal 4 to 5 times that of thallium dope...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/34C30B15/00C30B33/02
Inventor 沈思情刘浦锋肖型奎宋洪伟陈猛
Owner SHANGHAI ADVANCED SILICON TECH CO LTD
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