Preparation method of divalent metal cation and Ce co-doped LuAG crystal

Abstract

The invention discloses a divalent metal cation and Ce co-doped LuAG crystal and a preparation method thereof. The crystal has the chemical formula of M3xCe3yLu3(1-x-y)Al5O12. The method comprises thesteps as follows: the crystal grows with a medium frequency induction heating czochralski method, a heating element is an iraurita crucible, and raw materials are weighed in proportion after being calcined; the raw materials are pressed into a block by an isostatic press after being weighed, matched and uniformly ground and mixed, the block is sintered at the high temperature of 1,300 DEG C to besubjected to a solid phase reaction, and the sintered raw materials are stored in a drying oven; zirconium oxide and aluminum oxide are used as a thermal insulation cover and a thermal insulation material respectively, an observation port is sealed with a gem sheet, the inside of a combustion chamber is protected with inert gas in the growing process, the growth temperature of the crystal is about 1,970 DEG C, the pulling speed is 0.1-5 mm / h, and the rotation speed of the crystal is 5-30 rpm. The scintillation crystal has the advantages that the crystal growth cost is low, large size is easyto prepare, high-concentration doping is easy to realize, the scintillating property is outstanding and the like.

Description

technical field [0001] The present invention relates to scintillation crystal, particularly a kind of divalent cation and cerium ion co-doped LuAG (M 3x Ce 3y Lu 3(1-x-y) al 5 o 12 ) high temperature scintillation crystal and its preparation method. Background technique [0002] Inorganic scintillation crystals are crystalline energy converters that can convert the energy of high-energy photons (X / γ-rays) or particles (protons, neutrons, etc.) into easily detectable ultraviolet / visible photons. Detectors made of scintillation crystals are widely used in fields such as high-energy physics, nuclear physics, imaging nuclear medicine diagnosis (XCT, PET, etc.), geological exploration, astronomy and space physics, and safety inspection. With the rapid development of nuclear detection and related technologies, its application fields are still expanding. Different application fields put forward higher and higher requirements for scintillation crystals. Traditional scintillati...

AI Technical Summary

Problems solved by technology

[0007] Ce:YAG has the following disadvantages as a scintillation crystal: 1) Due to the 3+ (R Ce =1.03nm) ions enter the YAG lattice to replace Y with smaller ionic radius 3+ (R Y =0.89nm), due to the large difference in ionic radius, the segregation coefficient of Ce ions in the YAG lattice is very small (~0.1), on the one hand, it leads to uneven distribution of Ce ions in the crystal, and at the same time, it is difficult to realize the Ce:YAG crystal High-concentration doping, on the other hand, due to the large difference in ionic radius, the stress in the crystal structure is large, and the crystal is easy to crack; 2) Ce:YAG crystal density is small (about 4.55g / cm 3 ) leads to a small cut-off energy when detecting high-energy rays, and has certain limitations in the detection of high-energy γ-rays; 3) Since the crystal grows in an inert atmosphere, oxygen vacancies will be generated due to lack of oxygen, and oxygen vacancies become electron traps or Loss of excitation energy through additional channels reduces the light yield of the scintillation crystal