A high-crystallinity double-phase glass-ceramic scintillator and its preparation method and application

Abstract

The present invention discloses a high-crystallinity twin-phase glass-ceramic scintillator and its preparation method and application, belonging to the technical field of solid luminescent materials. The present invention uses SiO2, Al2O3, BaO, and CaF2 as components, and externally dopes TbF3 to prepare a uniform mixed batch, heats to form a glass melt, and then rapidly cools and forms it, and heat-treats it to obtain the glass-ceramic scintillator. Through component design, the present invention in-situ precipitates BaAl2Si2O8 and CaF2 twin-phases in fluorine-oxygen glass, and its crystallinity is as high as 96.01% as confirmed by X-ray diffraction spectrum measurement. The glass-ceramic scintillator contains a large amount of crystal phases of rare earth luminescent ions Tb 3+ It provides a low phonon energy environment, which is beneficial to reducing the probability of its non-radiative transition and improving the luminescence efficiency under X-ray excitation; when the glass-ceramic scintillator is used as an X-ray imaging scintillator material, it has suitable luminescence properties, which can solve the problems of low light yield and poor imaging sensitivity of most existing glass-ceramic scintillators, and the preparation process is simple, which is suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid luminescent materials, and in particular relates to a high-crystallinity twin-phase glass-ceramic scintillator and a preparation method and application thereof. Background Art

[0002] X-rays, discovered by Roentgen in 1895, possess the characteristics of high energy and strong penetrating power. Subsequently, using X-rays, Fujifilm Corporation of Japan introduced digital X-ray imaging technology in 1981. This technology uses an imaging plate to record X-ray intensity contrast, a dedicated readout device to read the corresponding digital signal, and then a computer to process and create an image. Currently, X-ray imaging technology is widely used in medical diagnosis, non-destructive testing, and basic research. In terms of components, an X-ray imaging system consists of an X-ray tube, an X-ray scintillator, a detector, and a display. Clearly, the X-ray scintillator is a crucial component, and the development of new X-ray scintillators is crucial to further improve imaging quality.

[0003] A scintillator is a material that converts absorbed radiation energy into visible or ultraviolet light when exposed to high-energy electromagnetic waves such as X-rays. This light can be detected and measured by detectors (such as photomultiplier tubes or solid-state photodetectors), thereby locating and quantifying the radiation source. Scintillators are widely used in medical imaging, industrial non-destructive testing, and safety inspections. The continuous progress of society and science has placed higher demands on scintillators, including high stability, high spatial resolution, excellent radioluminescence, reasonable decay time, and low-cost preparation. At present, the scintillator materials with excellent performance are mainly scintillating single crystals.

[0004] Traditional single-crystal scintillators such as BGO, CsI:Tl, and YAG:Ce have drawbacks such as long preparation cycles, high costs, and inflexible device processing, which limit their further application. Perovskite scintillators are unstable in harsh environments such as high temperature, high humidity, and high-energy X-ray irradiation, and the disadvantage of containing lead increases the cost of their actual use. In recent years, glass-ceramic scintillators have attracted much attention due to their simple preparation process, low cost, and ease of molding. This has also laid the foundation for the development and application of high-performance, low-cost, large-area scintillator materials. However, the crystallinity of currently developed glass-ceramic scintillators is generally too low (less than approximately 70%), and a large number of defects exist at the amorphous-crystal interface, resulting in low light yield and poor imaging sensitivity in most existing glass-ceramic scintillators.

[0005] The Chinese patent with publication number CN117361887A and application date of October 9, 2023 discloses a lead-free glass ceramic scintillator and its preparation method and application. The molar ratios of its components are: SiO2: 35-55mol%, Na2CO3: 5-15mol%, Al2O3: 10-20mol%, CaCO3: 2-10mol%, NaF: 2-10mol%, LuF3: 3-15mol%, GdF3: 0-10mol%, CeF3: 0-5mol%. The technical solution of this invention solves the problem of practical application of the new lead-free scintillator, while reducing costs and improving performance. The invention has high scintillation performance while eliminating the environmental and human hazards of lead. Although the fluorescence intensity of the scintillator is much higher than that of traditional single crystal scintillators such as BGO, it is essentially a single crystal phase scintillator. The Chinese patent application number CN1715230A, filed on June 10, 2005, provides a composition and method for a scintillator array. Glass powder and scintillator are mixed together to obtain a final mixture as a raw material, wherein 40-80% is scintillator crystal and 20-60% is glass powder. The scintillator crystal includes crystals Tb-Lu-Al-O-Ce, LuSiO5:Ce, Gd2O2S:Pr, Ce, F, Gd3Ga5O 12 :Cr, Ce, LuAlO3:Ce, Y3Al5O 12 :Ce、Bi4Ge3O 12 and (Y 1.67 Gd 0.33 Eu 0.1 )O2, the scintillator can be used to manufacture a scintillator array suitable for a CT system, but no technical inspiration related to the "double-phase glass-ceramic scintillator" is given.

[0006] In order to solve the defects of the above-mentioned existing glass-ceramic scintillators, a new type of double-phase glass-ceramic scintillator with high crystallinity and suitable optical properties that can be used in the field of X-ray imaging is designed. It has important reference value and innovative significance for the application scenarios and research directions of scintillators. Summary of the Invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a high crystallinity double-phase glass ceramic scintillator and its preparation method and application, wherein the glass ceramic scintillator contains a large number of crystal phases which can be rare earth luminescent ions Tb 3+ Providing a low phonon energy environment is beneficial to reducing the probability of its non-radiative transition and improving the luminescence efficiency under X-ray excitation.

[0008] The technical solutions of the present invention are as follows:

[0009] One of the purposes of the present invention is to provide a high-crystallinity twin-phase glass-ceramic scintillator, the molar ratios of its components are: 49.41 mol% SiO2, 10.59 mol% Al2O3, 20 mol% BaO, 20 mol% CaF2, the total molar amount of the above components is 100 mol%, and 0.01-14 mol% TbF3 is doped.

[0010] A second object of the present invention is to provide a method for preparing a high-crystallinity double-phase glass-ceramic scintillator, comprising the following steps:

[0011] (1) Design the precursor glass matrix and weigh the powder raw materials according to the component ratio. The component contents are as follows:

[0012] 49.41 mol% SiO2, 10.59 mol% Al2O3, 20 mol% BaO, 20 mol% CaF2, the total molar amount of the above components is 100 mol%, and 0.01-14 mol% TbF3 is added externally;

[0013] (2) Grinding the powder raw material uniformly and placing it in a crucible, melting it in a high-temperature furnace, and then quickly pouring the precursor glass melt into a preheated copper mold. After forming, it is quickly placed in a muffle furnace for annealing to obtain the precursor glass;

[0014] (3) The precursor glass is placed in a muffle furnace for heat preservation, inducing the in-situ precipitation of BaAl2Si2O8 crystal phase and CaF2 crystal phase in the glass, thereby preparing the glass-ceramic scintillator.

[0015] Furthermore, the melting temperature of the high-temperature furnace in step (2) is 1500-1600°C.

[0016] Furthermore, the melting time in step (2) is 25-35 minutes.

[0017] Furthermore, the preheating temperature of the copper mold in step (2) is 180-220°C.

[0018] Furthermore, the annealing temperature in the muffle furnace in step (2) is 380-420°C.

[0019] Furthermore, the annealing time in the muffle furnace in step (2) is 5-7 hours.

[0020] Furthermore, the insulation temperature in the muffle furnace in step (3) is 800-900°C.

[0021] Furthermore, the holding time in the muffle furnace in step (3) is 2-3 hours.

[0022] A third object of the present invention is to provide a high-crystallinity double-phase glass-ceramic scintillator for use in X-ray imaging.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Through component design, the present invention precipitates BaAl2Si2O8 and CaF2 twin phases in situ in oxyfluoride glass. X-ray diffraction spectrum measurement confirms that the crystallinity is as high as 96.01%. The glass ceramic scintillator contains a large amount of crystalline phases of rare earth luminescent ions Tb 3+ It provides a low phonon energy environment, which is beneficial to reducing the probability of its non-radiative transition and improving the luminous efficiency under X-ray excitation, and can solve the problems of low light yield and poor imaging sensitivity of most existing glass-ceramic scintillators.

[0025] 2. Residual internal stresses are effectively eliminated during the preparation of the dual-phase glass-ceramic scintillator, preventing cracking of the glass block. This helps maintain its initial state under high-energy radiation, resulting in improved stability and practical applicability. When used as a scintillator material for X-ray imaging, the dual-phase glass-ceramic scintillator exhibits suitable optical and luminescent properties, enabling clear observation of the internal structure of target objects and producing high-quality X-ray imaging results. This innovation is of significant significance to the research field of glass-ceramic scintillators.

[0026] 3. The preparation method of the twin-phase glass-ceramic scintillator provided by the present invention is simple, the preparation cycle is short, and it has a reasonable and clear raw material composition and low raw material cost. It is very suitable for industrial production and has high commercial value and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a differential scanning calorimetry test diagram of the precursor glass in Example 2 of the present invention;

[0028] Figure 2 X-ray diffraction patterns of the precursor glass and the high crystallinity dual-phase glass-ceramic in Example 2 of the present invention;

[0029] Figure 3 The UV-visible-near infrared transmission spectrum of the high crystallinity dual-phase glass-ceramic in Example 2 of the present invention;

[0030] Figure 4 This is an X-ray induced luminescence spectrum of the high crystallinity twin-phase glass-ceramic in Example 2 of the present invention;

[0031] Figure 5 This is an X-ray imaging photograph of the high crystallinity twin-phase glass-ceramic in Example 2 of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with preferred embodiments. The endpoints of the ranges and any values ​​disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0033] Unless otherwise specified, the experimental methods in the following examples are conventional methods and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0034] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0035] Example 1

[0036] This embodiment provides a method for preparing a high-crystallinity double-phase glass-ceramic scintillator, comprising the following steps:

[0037] S1. Analytically pure SiO2, Al2O3, BaCO3, CaF2 and 99.99% pure TbF3 powders are accurately weighed in a ratio of 49.41SiO2, 10.59Al2O3, 20BaO, 20CaF2, and 0.01TbF3 (molar ratio);

[0038] S2. Grind the powdered raw material evenly in an agate mortar and place it in an alumina crucible. Melt it in a 1500°C high-temperature furnace for 25 minutes. Then, quickly pour the precursor glass melt into a 180°C preheated copper mold. After forming, quickly anneal it in a 380°C muffle furnace for 5 hours to obtain the precursor glass.

[0039] S3. Keep the obtained precursor glass in a muffle furnace at 800° C. for 2 hours to induce the in-situ precipitation of BaAl2Si2O8 crystal phase and CaF2 crystal phase in the glass, thereby obtaining a high-crystallinity twin-phase glass-ceramic scintillator.

[0040] Example 2

[0041] This embodiment provides a method for preparing a high-crystallinity double-phase glass-ceramic scintillator, comprising the following steps:

[0042] S1. Analytically pure SiO2, Al2O3, BaCO3, CaF2 and 99.99% pure TbF3 powders are accurately weighed in a ratio of 49.41SiO2, 10.59Al2O3, 20BaO, 20CaF2, and 7TbF3 (molar ratio);

[0043] S2. Grind the powdered raw material uniformly in an agate mortar and place it in an alumina crucible. Melt it in a 1550°C high-temperature furnace for 30 minutes. Then, quickly pour the precursor glass melt into a 200°C preheated copper mold. After forming, quickly anneal it in a 400°C muffle furnace for 6 hours to obtain the precursor glass.

[0044] S3. Keep the obtained precursor glass in a muffle furnace at 850° C. for 2.5 hours to induce the in-situ precipitation of BaAl 2 Si 2 O 8 crystal phase and CaF 2 crystal phase in the glass, thereby obtaining a high-crystallinity twin-phase glass-ceramic scintillator.

[0045] Example 3

[0046] This embodiment provides a high-crystallinity double-phase glass-ceramic scintillator, the preparation method of which includes the following steps:

[0047] S1. Analytically pure SiO2, Al2O3, BaCO3, CaF2 and 99.99% pure TbF3 powder are accurately weighed in a ratio of 49.41SiO2, 10.59Al2O3, 20BaO, 20CaF2, and 14TbF3 (molar ratio).

[0048] S2. Grind the powdered raw material evenly in an agate mortar and place it in an alumina crucible. Melt it in a 1600°C high-temperature furnace for 35 minutes. Then, quickly pour the precursor glass melt into a 220°C preheated copper mold. After forming, quickly anneal it in a 420°C muffle furnace for 7 hours to obtain the precursor glass.

[0049] S3. Keep the obtained precursor glass in a muffle furnace at 900° C. for 3 hours to induce the in-situ precipitation of BaAl2Si2O8 crystal phase and CaF2 crystal phase in the glass, thereby obtaining a high-crystallinity twin-phase glass-ceramic scintillator.

[0050] Performance Testing

[0051] 1. The high crystallinity double-phase glass ceramic scintillator prepared in Example 2 was tested by differential scanning calorimetry. Figure 1 As shown in the differential scanning calorimetry test curve, the glass transition temperature T g , the first exothermic peak temperature T p1 , the second exothermic peak temperature T p2 They are approximately 697℃, 753℃ and 866℃ respectively. It is reasonable to choose 850℃ as the crystallization heat treatment temperature.

[0052] 2. The high crystallinity double-phase glass ceramic scintillator prepared in Example 2 was tested using an X-ray diffractometer. The X-ray diffraction pattern is as follows: Figure 2X-ray diffraction data showed that BaAl2Si2O8 and CaF2 crystal phases were precipitated in the glass matrix after heat treatment. The calculated corresponding crystallinity was 96.01%, successfully obtaining high crystallinity twin-phase glass ceramics.

[0053] 3. The high crystallinity double-phase glass-ceramic scintillator prepared in Example 2 was tested using an ultraviolet / visible / near-infrared spectrophotometer. The ultraviolet-visible-near-infrared transmission spectrum was as follows: Figure 3 The results of UV-visible-near infrared transmission spectrum show that the visible light transmittance of the high crystallinity dual-phase glass-ceramics is greater than 50%, indicating that it is transparent.

[0054] 4. The steady-state emission spectrum of the high-crystallinity double-phase glass-ceramic scintillator under X-ray irradiation was measured using the FLS1000 fluorescence spectrometer combined with a self-made test system consisting of an X-ray source, an integrating sphere, a sample stage, and the FLS1000 fluorescence spectrometer. The X-ray excited luminescence spectrum is shown in the figure below. Figure 4 As shown in the figure, obvious luminescence can be observed, among which the peaks at 415nm and 437nm are respectively attributed to Tb 5 D3 to 7 F5 and 7 The transition of F4, the peaks at 489nm, 545nm, 586nm, and 623nm are respectively attributed to Tb 5 D4 to 7 F6, 7 F5, 7 F4, 7 F3 transition.

[0055] 5. Use the high crystallinity double-phase glass ceramic to obtain X-ray imaging photos, such as Figure 5 As shown, the internal structure of the target object can be clearly observed and high-quality X-ray imaging results can be obtained.

[0056] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high crystallinity double-phase glass ceramic scintillator, characterized in that: The molar proportions of its components are: 49.41mol% SiO2, 10.59mol% Al2O3, 20mol% BaO, 20mol% CaF2, the total molar amount of the above components is 100mol%, and 0.01-14mol% TbF3 is added externally.

2. A method for preparing a high-crystallinity double-phase glass-ceramic scintillator, characterized in that: The following steps are involved: (1) Design the precursor glass matrix and weigh the powder raw materials according to the component ratio. The component contents are as follows: 49.41mol% SiO2, 10.59mol% Al2O3, 20mol% BaO, 20mol% CaF2, the total molar amount of the above components is 100mol%, and 0.01-14mol% TbF3 is added; (2) Grind the powder raw material evenly and place it in a crucible, then melt it in a high-temperature furnace. Then quickly pour the precursor glass melt into a preheated copper mold. After forming, quickly place it in a muffle furnace for annealing to obtain the precursor glass. (3) The precursor glass is placed in a muffle furnace for heat preservation, inducing the in-situ precipitation of BaAl2Si2O8 crystal phase and CaF2 crystal phase in the glass, thereby preparing the glass-ceramic scintillator.

3. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: The melting temperature of the high-temperature furnace in step (2) is 1500-1600°C.

4. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: The melting time in step (2) is 25-35 minutes.

5. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: The preheating temperature of the copper mold in step (2) is 180-220°C.

6. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: The annealing temperature in the muffle furnace in step (2) is 380-420°C.

7. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: The annealing time in the muffle furnace in step (2) is 5-7 hours.

8. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: In step (3), the insulation temperature in the muffle furnace is 800-900°C.

9. The method for preparing a high crystallinity double-phase glass-ceramic scintillator according to claim 2, characterized in that: The holding time in the muffle furnace in step (3) is 2-3 hours.

10. Use of a high-crystallinity double-phase glass-ceramic scintillator prepared by the preparation method according to any one of claims 2 to 9 in X-ray imaging.

Images