Application of rubidium lithium titanium germanate as scintillation crystal

Abstract

The invention provides an application of rubidium lithium titanium germanate as a scintillation crystal. The chemical formula of the scintillation crystal rubidium lithium titanium germanate provided by the invention is Rb4Li2TiOGe4O12, the scintillation crystal has the advantages of intrinsic luminescence, no deliquescence, high energy resolution, high scintillation luminescence efficiency and the like, and the light yield of the scintillation crystal is high and is about 12,000 ph / MeV. And the scintillation crystal generates visible light emission with the wavelength of about 484 nm under the excitation of X rays. The scintillation crystal can be used in the fields of X-ray and high-energy particle detection and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of scintillation materials, and in particular to the use of rubidium lithium titanate germanate as a scintillation crystal. Background Art

[0002] Scintillating crystals are photon-converting crystal materials that absorb the energy of incident high-energy radiation (such as X-rays and gamma rays) or high-energy particle beams and convert it into a lower-energy state, releasing it as a large number of photons. Leveraging this scintillation effect, scintillating crystals are widely used in nuclear physics, high-energy physics, space physics, nuclear medicine imaging, geological exploration, and security inspections. Inorganic scintillating crystals, with their high density, strong stability, transparency, and excellent scintillation properties, have become the mainstay of scintillating material development.

[0003] The luminescence mechanism of inorganic scintillating crystals can be divided into two types, namely intrinsic luminescence and extrinsic luminescence. The intrinsic luminescence center mainly includes self-trapped excitons, constituent atoms or groups of the matrix, and various defects in the crystal structure. Currently, there are few scintillating crystals that can emit intrinsic light, mainly Bi4Ge3O 12 (BGO) crystals are widely used in high-energy ion detection and medical fields. The extrinsic luminescence centers mainly come from the activated ions artificially introduced into the crystal matrix. The main doping ions in the scintillation crystals of extrinsic luminescence are rare earth elements such as Ce. 3+ and Eu 2+ and other ions such as Tl + The commercially used extrinsic luminescence scintillating crystals mainly include LaBr3:Ce 3+ ,(Lu,Y)2SiO5:Ce 3+ , SrI2:Eu 2+ , CsI:Tl + For scintillating crystals with non-intrinsic luminescence, the introduction of activating ions causes component segregation, resulting in a non-uniform distribution throughout the crystal. This leads to non-uniform scintillation performance, which inevitably reduces the ultimate energy resolution of the scintillating crystal material. Therefore, new scintillating crystals with high resolution and intrinsic luminescence have broader application prospects and practical value. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention provides the use of rubidium lithium titanate germanate as a scintillation crystal. Under X-ray excitation, the scintillation crystal has an emission peak at 484 nm and a light yield of approximately 12,000 ph / MeV, significantly superior to the commercial intrinsic scintillator BGO crystal (8,000 ph / MeV).

[0005] The present invention specifically provides the following technical solutions:

[0006] The invention discloses a use of rubidium lithium titanate germanate as a scintillation crystal.

[0007] According to an embodiment of the present invention, the rubidium lithium titanate germanate is used as a scintillation crystal for intrinsic luminescence.

[0008] According to an embodiment of the present invention, the rubidium lithium titanate germanate does not contain dopant ions.

[0009] According to an embodiment of the present invention, the chemical formula of the rubidium lithium titanium germanate is Rb4Li2TiOGe4O 12 (RLTG).

[0010] According to an embodiment of the present invention, the crystal of rubidium lithium titanate germanate belongs to the tetragonal system and the space group is P4nc.

[0011] According to an embodiment of the present invention, the molecular weight of the rubidium lithium titanate germanate is 902.02 g / mol; the unit cell parameters are

[0012] According to an embodiment of the present invention, the rubidium lithium titanate germanate is a polycrystalline powder structure or a large-scale crystal structure.

[0013] According to an embodiment of the present invention, the rubidium lithium titanate germanate can be prepared by methods known in the art.

[0014] According to an embodiment of the present invention, the polycrystalline powder structure of rubidium lithium titanate germanate is prepared, for example, by the following method:

[0015] The Rb-containing compound, the Li-containing compound, the Ti-containing compound and the Ge-containing compound are ground and mixed, pre-fired at 500-600° C. for more than 24 hours, cooled to room temperature, ground and mixed again, and then sintered at 700-850° C. for more than 12 hours.

[0016] According to an embodiment of the present invention, the Rb-containing compound is one or more of Rb oxide, Rb hydroxide, Rb carbonate, Rb halide, Rb nitrate or Rb oxalate; the Li-containing compound is one or more of Li oxide, Li hydroxide, Li carbonate, Li halide, Li nitrate or Li oxalate; the Ti-containing compound is one or more of Ti oxide, Ti hydroxide, Ti halide, Ti nitrate or Ti oxalate; the Ge-containing compound is one or more of Ge oxide, Ge hydroxide, Ge halide, Ge nitrate or Ge oxalate.

[0017] According to an embodiment of the present invention, the molar ratio of Rb, Li, Ti and Ge elements in the Rb-containing compound, the Li-containing compound, the Ti-containing compound and the Ge-containing compound is 4:2:1:4.

[0018] According to an embodiment of the present invention, the Rb-containing compound, the Li-containing compound, the Ti-containing compound and the Ge-containing compound are ground and mixed, heated to 500-600°C at a heating rate of 10-50°C / h and pre-fired for more than 24 hours, cooled to room temperature and then ground and mixed again, and then heated to 700-850°C at a heating rate of 10-50°C / h and sintered for more than 12 hours.

[0019] According to an embodiment of the present invention, the large-scale crystal structure of rubidium lithium titanate germanate is prepared, for example, by the following method:

[0020] (1) grinding and mixing a Rb-containing compound, a Li-containing compound, a Ti-containing compound, a Ge-containing compound, and a flux to obtain a raw material; or grinding and mixing the polycrystalline powder structure of rubidium lithium titanate germanate prepared above and a flux to obtain a raw material;

[0021] (2) melting the raw materials and heating them to 700-950°C, stirring at a constant temperature to obtain a melt;

[0022] (3) Cool the melt and introduce a seed crystal at a temperature 2 to 10°C above the melt saturation point. Cool the melt at a rate of 0.1 to 5°C / day and rotate the crystal at a speed of 15 to 50 r / min to start crystal growth. After the crystal growth is completed, lift the crystal from the liquid surface and anneal it to room temperature at a cooling rate of no more than 100°C / h.

[0023] According to an embodiment of the present invention, the flux includes one or more of RbF, LiF and MoO3.

[0024] According to an embodiment of the present invention, the molar ratio of the flux to the Ti element in the Ti-containing compound is 2-5:1.

[0025] According to an embodiment of the present invention, the Rb-containing compound is one or more of Rb oxide, Rb hydroxide, Rb carbonate, Rb halide, Rb nitrate or Rb oxalate; the Li-containing compound is one or more of Li oxide, Li hydroxide, Li carbonate, Li halide, Li nitrate or Li oxalate; the Ti-containing compound is one or more of Ti oxide, Ti hydroxide, Ti halide, Ti nitrate or Ti oxalate; the Ge-containing compound is one or more of Ge oxide, Ge hydroxide, Ge halide, Ge nitrate or Ge oxalate.

[0026] According to an embodiment of the present invention, the molar ratio of Rb, Li, Ti and Ge elements in the Rb-containing compound, the Li-containing compound, the Ti-containing compound and the Ge-containing compound is 4:2:1:4.

[0027] According to an embodiment of the present invention, the emission peak of the scintillation crystal is located at 484 nm under X-ray excitation.

[0028] According to an embodiment of the present invention, the light yield of the scintillation crystal is about 12,000 ph / MeV.

[0029] The present invention also provides a device, comprising a scintillation crystal, wherein the scintillation crystal comprises rubidium lithium titanate germanate.

[0030] According to an embodiment of the present invention, the chemical formula of the rubidium lithium titanium germanate is Rb4Li2TiOGe4O 12 .

[0031] According to an embodiment of the present invention, the rubidium lithium titanate germanate is defined as described above.

[0032] Beneficial effects of the present invention:

[0033] The present invention provides a use of rubidium lithium titanate germanate as a scintillation crystal. The chemical formula of the scintillation crystal rubidium lithium titanate germanate provided by the present invention is Rb4Li2TiOGe4O 12 The scintillation crystals have advantages such as intrinsic luminescence, non-deliquescent properties, high energy resolution, and high scintillation efficiency. They also have a high light yield of approximately 12,000 ph / MeV. When excited by X-rays, they emit visible light with a wavelength of approximately 484 nm. They can be used in fields such as X-ray and high-energy particle detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The Rb4Li2TiOGe4O provided by the present invention is shown 12 Schematic diagram of the crystal structure of a scintillation crystal.

[0035] Figure 2 The Rb4Li2TiOGe4O provided by the present invention is shown 12 Schematic diagram of the principle of scintillation effect produced by scintillation crystals under X-ray excitation.

[0036] Figure 3 The Rb4Li2TiOGe4O provided by the present invention is shown 12 X-ray excitation emission spectrum of scintillation crystals.

[0037] Figure 4 The Rb4Li2TiOGe4O provided by the present invention is shown12 Quantitative comparison of the light yield of scintillation crystals. DETAILED DESCRIPTION

[0038] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0039] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the reagents, materials, etc. used in the following examples are all commercially available unless otherwise specified.

[0040] Example 1

[0041] Preparation of scintillating crystal Rb4Li2TiOGe4O by solid phase reaction method 12 Solid phase powder, the reaction equation is 2Rb2CO3+Li2CO3+TiO2+4GeO2=Rb4Li2TiOGe4O 12 ; The feeding ratio of the above four reaction raw materials is Rb2CO3 (4.619g, 0.02mol), Li2CO3 (0.739g, 0.01mol), TiO2 (0.799g, 0.01mol), and GeO2 (4.186g, 0.04mol).

[0042] Scintillating crystal Rb4Li2TiOGe4O 12 The specific preparation steps are as follows: four reaction raw materials are weighed according to the above dosages, the reaction raw materials are placed in a mortar, ground and mixed, then placed in a platinum crucible, placed in a muffle furnace, heated to 500°C at a rate of 50°C / h for pre-sintering, kept warm for 24 hours and then cooled, after cooling to room temperature, the sample is taken out and ground and mixed again, then placed in a muffle furnace, heated to 750°C at a rate of 50°C / h and sintered for 12 hours, and after cooling, a sample with a chemical formula of Rb4Li2TiOGe4O is obtained. 12 of polycrystalline powder.

[0043] Example 2

[0044] Preparation of scintillation crystal Rb4Li2TiOGe4O by flux method 12 The method comprises the following steps: using LiF as a flux, weighing 902.172 g of Rb4Li2TiOGe4O prepared in Example 1 at a solute to solvent molar ratio of 1:3, 12Polycrystalline powder (1 mol) and 77.818 g of LiF (3 mol) were ground and mixed in a mortar, melted in batches, and loaded into a Φ80 mm × 80 mm crucible. The crucible was placed in a vertical crystal growth furnace, heated to 850°C, stirred at a constant temperature for 48 hours, and then cooled to 5°C above the saturation point. A seed crystal was introduced and the temperature was cooled at a rate of 0.5°C / day with a rotation speed of 10 r / min to start crystal growth. After the crystal growth was completed, the seed crystal rod was lifted and the crystal was lifted out of the liquid surface. The temperature was then cooled to room temperature at a rate of 20°C / h to obtain transparent Rb4Li2TiOGe4O 12 Large size (4mm×5mm×6mm) crystal.

[0045] Figure 3 The Rb4Li2TiOGe4O provided by the present invention is shown 12 X-ray excitation emission spectrum of scintillation crystal. Figure 3 It can be seen that under X-ray excitation, the Rb4Li2TiOGe4O prepared in Example 2 12 Large-sized crystals emit bright blue light with a central wavelength of about 484 nm, namely Rb4Li2TiOGe4O 12 The X-ray excitation emission peak of the scintillation crystal is located at 484nm. Figure 4 As shown in the figure, under the same test conditions, the light yield of the RLTG scintillation crystal is about 12000ph / MeV, which is significantly better than the light yield of the commercial intrinsic scintillator BGO crystal (8000ph / MeV).

[0046] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. Use of rubidium lithium titanate germanate as a scintillation crystal.

2. The use according to claim 1, wherein The rubidium lithium titanate germanate is used as a scintillation crystal for intrinsic luminescence.

3. The use according to claim 1 or 2, wherein The chemical formula of the rubidium lithium titanium germanate is Rb4Li2TiOGe4O 12 .

4. The use according to any one of claims 1 to 3, wherein The crystal of the rubidium lithium titanate germanate belongs to the tetragonal system and has a space group of P4nc.

5. The use according to any one of claims 1 to 4, wherein The rubidium lithium titanate germanate is a polycrystalline powder structure or a large-size crystal structure.

6. The use according to any one of claims 1 to 5, wherein When excited by X-rays, the scintillation crystal has an emission peak at 484 nm.

7. The use according to any one of claims 1 to 6, wherein The light yield of the scintillation crystal is 12000 ph / MeV.

8. A device, wherein: The device includes a scintillation crystal comprising rubidium lithium titanate germanate.

9. The device according to claim 8, wherein The chemical formula of the rubidium lithium titanium germanate is Rb4Li2TiOGe4O 12 .

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