Cerium-doped yttrium lithium silicate, and preparation method and application thereof

Abstract

The application discloses cerium-doped yttrium lithium silicate and a preparation method and application thereof, and the preparation method comprises the following steps: S1, mixing Li2CO3, Y2O3, SiO2 and CeF3, and performing first sintering to obtain initial sintered powder; S2, performing second sintering on the initial sintered powder to obtain cerium-doped yttrium lithium silicate (LiYSiO4); wherein, in step S1, the temperature of the first sintering is 600-800 DEG C; and in step S2, the temperature of the second sintering is 1000-1200 DEG C. The photoluminescence decay time of the cerium-doped yttrium lithium silicate prepared by the application is below 50 ns, which is beneficial to effectively reducing residual image residues in the X-ray imaging process and effectively improving the definition and time resolution of X-ray imaging.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic materials technology, and more specifically, to a cerium-doped yttrium silicate, its preparation method, and its applications. Background Technology

[0002] High-energy rays (typically X-rays) can interact with shell electrons within materials, thereby obtaining supplementary information about the material's atomic composition. Due to this property, X-ray imaging equipment has been widely used in clinical medical diagnosis, industrial non-destructive testing, and cutting-edge scientific research. Currently, detection and imaging technologies for high-energy radiation are mainly divided into two types: direct detection and indirect detection. Direct detectors are mostly made of semiconductor materials, with cadmium zinc telluride (Cd) being a typical example. x Zn 1-x Te, CZT), amorphous selenium (Se), high-purity germanium (Ge), and various metal halide compounds that combine high energy resolution and high spatial resolution; compared with direct detection technology, indirect detection has become the mainstream choice in the field of high-energy radiation imaging due to its advantages such as mature preparation process, controllable cost, good device stability, suitability for large-area imaging scenarios, and excellent resistance to radiation damage. This technology uses scintillator materials to achieve energy conversion, first converting the high-energy signal of high-energy particles / rays into light pulse signals, and then further converting the light pulse signals into collectable and analyzable electrical signals through various photodetectors such as photomultiplier tubes (PMTs), silicon photomultiplier tubes (SiPMs), and complementary metal-oxide semiconductors (CMOS). At present, there is a wide variety of common scintillator oxide materials suitable for high-energy radiation detection and X-ray imaging. The mainstream materials include cerium-doped rare earth silicate series, represented by lutetium yttrium silicate, lutetium silicate, and lutetium gadolinium silicate.

[0003] In the field of high-energy particle and ray imaging, whether it is static X-ray imaging or dynamic X-ray imaging, in order to effectively reduce the afterimages during the imaging process and improve the imaging clarity and temporal resolution, stringent requirements are placed on the response speed of the core devices. This also means that the scintillator material used must have a short photoluminescence decay time, relying on the fast decay characteristics to meet the actual needs of high-quality imaging.

[0004] Therefore, it is of great significance to develop a method for preparing cerium-doped yttrium silicate with a photoluminescence decay time ≤50ns. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cerium-doped yttrium silicate, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for preparing cerium-doped yttrium silicate lithium, comprising the following steps: S1. Mix Li2CO3, Y2O3, SiO2 and CeF3, and perform the first sintering to obtain the initial sintered powder; S2. The initial sintered powder is sintered a second time to obtain cerium-doped lithium yttrium silicate (LiYSiO4). In step S1, the temperature of the first sintering is 600-800℃; In step S2, the temperature of the second sintering is 1000-1200℃.

[0007] This invention reduces the content of the lithium yttrium silicate impurity phase LiY9(SiO4)6O2 in cerium-doped lithium yttrium silicate by simultaneously using CeF3 and conducting a first and second sintering at specific temperatures, while increasing the content of the pure lithium yttrium silicate phase LiYSiO4. This suppresses lattice distortion in cerium-doped lithium yttrium silicate, thereby reducing the photoluminescence decay time of cerium-doped lithium yttrium silicate to below 50 ns. This, in turn, helps to effectively reduce image retention during X-ray imaging and effectively improve the clarity and temporal resolution of X-ray imaging.

[0008] Preferably, in step S1, the temperature of the first sintering is one or any two of 600℃, 630℃, 650℃, 680℃, 700℃, 730℃, 750℃, 780℃, and 800℃.

[0009] Preferably, in step S2, the temperature of the second sintering is one or any two of the following: 1000℃, 1030℃, 1050℃, 1080℃, 1100℃, 1130℃, 1150℃, 1180℃, and 1200℃.

[0010] Preferably, the mass ratio of SiO2 to CeF3 is 1:(0.01-0.1).

[0011] Preferably, the mass ratio of SiO2 to CeF3 is one of or between any two of the following: 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, and 1:0.1.

[0012] More preferably, the mass ratio of SiO2 to CeF3 is 1:(0.03-0.08).

[0013] Preferably, the mass ratio of SiO2 to Y2O3 is 1:(1.70-2.40).

[0014] Preferably, the mass ratio of SiO2 to Y2O3 is one of or between any two of the following: 1:1.70, 1:1.75, 1:1.80, 1:1.85, 1:1.90, 1:1.95, 1:2.00, 1:2.05, 1:2.10, 1:2.15, 1:2.20, 1:2.25, 1:2.30, 1:2.35, and 1:2.40.

[0015] Preferably, the mass ratio of SiO2 to Li2CO3 is 1:(0.50-0.75).

[0016] Preferably, the mass ratio of SiO2 to Li2CO3 is one of 1:0.50, 1:0.55, 1:0.60, 1:0.65, 1:0.70, 1:0.75 or any value between the two.

[0017] Preferably, the first sintering time is 4-8 hours, specifically 6 hours.

[0018] Preferably, the first sintering time is one of 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h or any range between two of them.

[0019] Preferably, the gas atmosphere for the first sintering includes a reducing gas.

[0020] More preferably, the reducing gas includes at least one of hydrogen and carbon monoxide.

[0021] More preferably, the gas atmosphere for the first sintering also includes an inert gas.

[0022] More preferably, the inert gas includes at least one of argon and nitrogen.

[0023] More preferably, the gas atmosphere for the first sintering includes hydrogen and argon, and the volume ratio of hydrogen to argon is (3-20):(97-80).

[0024] More preferably, the gas atmosphere for the first sintering includes hydrogen and argon, and the volume ratio of hydrogen to argon is (5-20):(95-80), specifically 5:95.

[0025] Preferably, the second sintering time is 8-12 hours, specifically 8-10 hours.

[0026] Preferably, the second sintering time is one of 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h or any range between two of them.

[0027] Preferably, the gas atmosphere for the second sintering includes a reducing gas.

[0028] More preferably, the reducing gas includes at least one of hydrogen and carbon monoxide.

[0029] More preferably, the gas atmosphere for the second sintering also includes an inert gas.

[0030] More preferably, the inert gas includes at least one of argon and nitrogen.

[0031] More preferably, the gas atmosphere of the second sintering includes hydrogen and argon, and the volume ratio of hydrogen to argon is (3-20):(97-80).

[0032] More preferably, the gas atmosphere for the first sintering includes hydrogen and argon, and the volume ratio of hydrogen to argon is (5-20):(95-80), specifically 5:95.

[0033] Preferably, after the first sintering, the process further includes cooling to room temperature.

[0034] Preferably, after the second sintering, the process further includes cooling to room temperature.

[0035] In a second aspect, the present invention provides a cerium-doped yttrium silicate lithium, which is prepared by the preparation method described in the first aspect.

[0036] Thirdly, the present invention provides an application of cerium-doped yttrium silicate lithium in scintillator materials.

[0037] Fourthly, the present invention provides a composite scintillator film comprising thermoplastic polyurethane (TPU) and the aforementioned cerium-doped yttrium silicate lithium.

[0038] Preferably, the mass ratio of the thermoplastic polyurethane (TPU) to cerium-doped yttrium silicate is 100:(50-5), specifically 100:30.

[0039] Fifthly, the present invention provides a method for preparing a composite scintillator thin film, comprising the following steps: A mixed solution is obtained by mixing thermoplastic polyurethane (TPU), cerium-doped yttrium lithium silicate, and a solvent. The solution is then electrospun into a film to obtain a composite scintillator film.

[0040] Preferably, the mass ratio of the thermoplastic polyurethane (TPU) to the volume ratio of the solvent is (0.5-10)g:(3-20)mL, specifically 2.5g:12mL.

[0041] Preferably, the solvent includes at least one of N,N-dimethylformamide (DMF), tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), dichloromethane (DCM), and xylene (XYL).

[0042] More preferably, the solvent comprises N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) in a volume ratio of 1:(0.1-1.5).

[0043] More preferably, the volume ratio of N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) is one of or between any two of the following: 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, and 1:1.5.

[0044] Preferably, the mixing temperature is 25-80°C, specifically 60°C.

[0045] Preferably, the electrospinning temperature is 25-60℃, specifically 30℃.

[0046] Preferably, the voltage for electrospinning is 16-36kV, specifically 21kV.

[0047] Preferably, the electrospinning speed is 0.5-2.5 mL / h, specifically 1 mL / h.

[0048] Preferably, the distance from the needle to the roller in the electrospinning process is 5-25cm, specifically 12cm.

[0049] In a sixth aspect, the present invention provides an application of a composite scintillator thin film in X-ray imaging.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention reduces the content of the lithium yttrium silicate impurity phase LiY9(SiO4)6O2 in cerium-doped lithium yttrium silicate by simultaneously using CeF3 and conducting a first and second sintering at specific temperatures, while increasing the content of the pure lithium yttrium silicate phase LiYSiO4. This suppresses lattice distortion in cerium-doped lithium yttrium silicate, thereby reducing the photoluminescence decay time of cerium-doped lithium yttrium silicate to below 50 ns. This, in turn, helps to effectively reduce image retention during X-ray imaging and effectively improve the clarity and temporal resolution of X-ray imaging. Attached Figure Description

[0051] Figure 1Figure 1 shows the SEM and EDS spectra of cerium-doped yttrium silicate lithium in Example 1. Figure 1a is the SEM image of cerium-doped yttrium silicate lithium in Example 1, Figure 1b is the EDS spectrum of silicon in cerium-doped yttrium silicate lithium in Example 1, Figure 1c is the EDS spectrum of yttrium in cerium-doped yttrium silicate lithium in Example 1, and Figure 1d is the EDS spectrum of cerium in cerium-doped yttrium silicate lithium in Example 1.

[0052] Figure 2 The figures show the XRD patterns and XRD refinement results of cerium-doped lithium yttrium silicate. Figure a shows the XRD patterns of cerium-doped lithium yttrium silicate in Example 1 and Comparative Example 8, and Figure b shows the refinement results of cerium-doped lithium yttrium silicate in Example 1.

[0053] Figure 3 The image shows the time-resolved spectrum of cerium-doped yttrium silicate under 350 nm pulsed laser excitation in Example 1.

[0054] Figure 4 The figures show the photoluminescence spectrum of cerium-doped yttrium silicate in Example 1, as well as the photoluminescence intensity versus temperature fitting graph. Figure a shows the photoluminescence spectrum of cerium-doped yttrium silicate in Example 1 within the temperature range of 300K-500K, and Figure b shows the photoluminescence intensity versus temperature fitting graph of cerium-doped yttrium silicate in Example 1.

[0055] Figure 5 Figure a shows an uncut photograph of the composite scintillator film of Application Example 1 and a photograph under ultraviolet light irradiation. Figure b shows a photograph of the composite scintillator film of Application Example 1 under ultraviolet light irradiation at a wavelength of 365 nm.

[0056] Figure 6 Figure a shows the cut image of the composite scintillator film of Application Example 1 and the image under ultraviolet light irradiation. Figure b shows the cut image of the composite scintillator film of Application Example 1 and the image under ultraviolet light irradiation at a wavelength of 365 nm.

[0057] Figure 7 The image shows the X-ray lead plate edge resolution analysis of the composite scintillator thin film used in Example 1.

[0058] Figure 8 The images shown are X-ray images of the composite scintillator thin film used in Example 1. Figure a is a picture of the chip itself, and Figure b is an X-ray image of the chip using the composite scintillator thin film used in Example 1. Detailed Implementation

[0059] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0060] In the following examples, experimental methods without specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer. Unless otherwise specified, all raw materials and reagents used are commercially available from the general market. Furthermore, unless otherwise specified, "parts" and "%" refer to mass measurements.

[0061] The reagents used in the various embodiments and comparative examples of this invention are as follows: Thermoplastic polyurethane (TPU), TT-1069D, Lubrizol, USA.

[0062] Example 1 This embodiment provides a cerium-doped yttrium silicate lithium, the preparation method of which includes the following steps: S1. Grind and mix Li2CO3, Y2O3, SiO2 and CeF3, place them in a tube furnace, and sinter at 800℃ for 6 hours in a mixed gas atmosphere of hydrogen and argon with a volume ratio of 5:95 at a heating rate of 4℃ / min. Cool to room temperature to obtain the initial sintered powder. S2. Grind the initial sintering powder, place it in a tube furnace, and in a mixed gas atmosphere of hydrogen and argon with a volume ratio of 5:95, heat at a rate of 4℃ / min, and perform a second sintering at 1100℃ for 10h. Cool to room temperature to obtain cerium-doped yttrium silicate (LiYSiO4). The mass ratio of SiO2 to CeF3 is 1:0.05; the mass ratio of SiO2 to Y2O3 is 1:2.20; and the mass ratio of SiO2 to Li2CO3 is 1:0.65.

[0063] Examples 2-5 and Comparative Examples 1-6 Examples 2-5 and Comparative Examples 1-6 provide different cerium-doped yttrium silicate and their preparation methods. The difference between them and Example 1 lies in the temperature and time of the first and second sintering processes. The rest are the same as in Example 1, as shown in the table below: Table 1 Note: In the table above, Comparative Example 3 indicates that the first sintering was not performed, and Comparative Example 6 indicates that the second sintering was not performed.

[0064] Example 6 This embodiment provides a cerium-doped yttrium lithium silicate and its preparation method. The difference between this embodiment and Embodiment 1 is that after the first sintering, the sample is not cooled to room temperature, but directly subjected to a second sintering. The rest of the method is the same as in Embodiment 1, as detailed below: The method for preparing cerium-doped yttrium silicate includes the following steps: Li2CO3, Y2O3, SiO2 and CeF3 were ground and mixed, and placed in a tube furnace. In a mixed gas atmosphere of hydrogen and argon with a volume ratio of 5:95, the temperature was raised at 4℃ / min for the first sintering at 800℃ for 6 hours. Then, the temperature was raised to 1100℃ at a rate of 4℃ / min and sintered for the second time at 1100℃ for 10 hours. After cooling to room temperature, cerium-doped yttrium silicate (LiYSiO4) was obtained. The mass ratio of SiO2 to CeF3 is 1:0.05; the mass ratio of SiO2 to Y2O3 is 1:2.20; and the mass ratio of SiO2 to Li2CO3 is 1:0.65.

[0065] Examples 7-10 Examples 7-10 provide different cerium-doped yttrium lithium silicate and their preparation methods. The difference between these examples and Example 1 is that the mass ratio of SiO2 and CeF3 is different; otherwise, they are the same as in Example 1, as shown in the table below: Table 2 Comparative Example 7 This comparative example provides a cerium-doped lithium yttrium silicate and its preparation method. The difference between this example and Example 1 is that cerium dioxide (CeO2) is used instead of CeF3. All other aspects are the same as in Example 1, as detailed below: Comparative Example 8 This comparative example provides a cerium-doped yttrium silicate lithium, the preparation method of which includes the following steps: Li2CO3, Y2O3, SiO2 and CeO2 were ground and mixed, placed in a tube furnace, and sintered at 900°C for 16 hours in a mixed gas atmosphere of hydrogen and argon with a volume ratio of 5:95. After cooling to room temperature, cerium-doped yttrium silicate (LiYSiO4) was obtained. The mass ratio of SiO2 to CeO2 is 1:0.05; the mass ratio of SiO2 to Y2O3 is 1:2.20; and the mass ratio of SiO2 to Li2CO3 is 1:0.65.

[0066] Application Example 1 This application example provides a composite scintillator film comprising thermoplastic polyurethane (TPU) in a mass ratio of 100:30 and cerium-doped yttrium silicate prepared in Example 1; The method for preparing the composite scintillator thin film includes the following steps: (1) The cerium-doped lithium yttrium silicate prepared in Example 1 was ball-milled for 1 hour, passed through an 800-mesh sieve, and vacuum-dried at 80°C for 6 hours to obtain cerium-doped lithium yttrium silicate powder for later use. (2) Mix N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) in a volume ratio of 1:1 to obtain a solvent for later use; (3) Under the condition of constant temperature water bath at 60℃, 2.5g thermoplastic polyurethane (TPU), 0.75g cerium-doped yttrium lithium powder and 12mL solvent were mixed and stirred for 12h to obtain a mixed solution. The composite scintillator film was obtained by electrospinning. In step (3), the mass ratio of the thermoplastic polyurethane (TPU) to the cerium-doped yttrium lithium silicate powder is 100:30, the mass ratio of the thermoplastic polyurethane (TPU) to the volume ratio of the solvent is 2.5g:12mL, the electrospinning temperature is 30℃, the voltage is 21kV, the spinning speed is 1mL / h, and the distance from the needle to the roller is 12cm.

[0067] Figure 1 Figure 1 shows the SEM and EDS spectra of cerium-doped yttrium silicate lithium in Example 1. Figure 1a is the SEM image of cerium-doped yttrium silicate lithium in Example 1, Figure 1b is the EDS spectrum of silicon in cerium-doped yttrium silicate lithium in Example 1, Figure 1c is the EDS spectrum of yttrium in cerium-doped yttrium silicate lithium in Example 1, and Figure 1d is the EDS spectrum of cerium in cerium-doped yttrium silicate lithium in Example 1.

[0068] from Figure 1 It can be seen that the distribution of each element in the cerium-doped yttrium silicate prepared by this invention is relatively uniform, which also indicates that the Ce element (or Ce) is present in a relatively uniform manner. 3+ It is incorporated into the lattice of cerium-doped lithium yttrium silicate and is evenly distributed.

[0069] Figure 2 The figures show the XRD patterns and XRD refinement results of cerium-doped lithium yttrium silicate. Figure a shows the XRD patterns of cerium-doped lithium yttrium silicate in Example 1 and Comparative Example 8, and Figure b shows the refinement results of cerium-doped lithium yttrium silicate in Example 1.

[0070] from Figure 2 It can be seen that, compared with Comparative Example 8 which used CeO2 and a single sintering process (900℃, 6h), the cerium-doped yttrium silicate prepared by this invention has virtually no presence of the lithium yttrium silicate impurity phase LiY9(SiO4)6O2. This indicates that the simultaneous use of CeF3 and the first and second sintering processes at specific temperatures in this invention can reduce the content of the lithium yttrium silicate impurity phase LiY9(SiO4)6O2 in cerium-doped yttrium silicate, increase the content of the pure lithium yttrium silicate phase LiYSiO4, and suppress lattice distortion in cerium-doped yttrium silicate. This is beneficial for reducing the photoluminescence decay time of cerium-doped yttrium silicate, and thus for effectively reducing image retention during X-ray imaging and effectively improving the clarity and temporal resolution of X-ray imaging.

[0071] Performance testing The following performance tests were performed on the cerium-doped yttrium silicate of each embodiment and comparative example: 1. Test of the content of lithium yttrium silicate impurity phase LiY9(SiO4)6O2: At room temperature of 23°C, X-ray diffraction (XRD) tests and XRD data refinement were performed on cerium-doped yttrium silicate in each example and comparative example using a D8 Advance X-ray powder diffractometer from Bruker AXS GmbH, Germany, to obtain the content (wt%) of the lithium silicate impurity phase LiY9(SiO4)6O2 in cerium-doped yttrium silicate. 2. Test of photoluminescence decay time: At room temperature (23°C), the photoluminescence decay time-resolved tests of cerium-doped yttrium silicate in each embodiment and comparative example were performed using an FLS1000 steady-state transient fluorescence spectrometer (Edinburgh Ltd., UK). The time-resolved spectra of cerium-doped yttrium silicate under 350 nm pulsed laser excitation were obtained. The test results were then fitted and analyzed using the single exponential function correlation function built into the steady-state transient fluorescence spectrometer to finally obtain the corresponding photoluminescence decay times, for example... Figure 3 As shown; The experimental results are shown in the table below: Table 3. Sound absorption performance test results of cerium-doped lithium yttrium silicate in each embodiment and comparative example. Figure 3 The image shows the time-resolved spectrum of cerium-doped yttrium silicate under 350 nm pulsed laser excitation in Example 1. Figure 3 According to the single exponential function fitting, the photoluminescence decay time of cerium-doped yttrium silicate in Example 1 is 30.7 ns, which is considered fast decay.

[0072] from Figure 3 As shown in Table 3, by simultaneously using CeF3 and performing a first sintering and a second sintering at specific temperatures, this invention reduces the content of the lithium yttrium silicate impurity phase LiY9(SiO4)6O2 in cerium-doped lithium yttrium silicate, increases the content of the pure lithium yttrium silicate phase LiYSiO4, and suppresses lattice distortion in cerium-doped lithium yttrium silicate. This reduces the photoluminescence decay time of cerium-doped lithium yttrium silicate to below 50 ns, thereby effectively reducing image retention during X-ray imaging and improving the clarity and temporal resolution of X-ray imaging.

[0073] Figure 4The figures show the photoluminescence spectrum of cerium-doped yttrium silicate in Example 1, as well as the photoluminescence intensity versus temperature fitting graph. Figure a shows the photoluminescence spectrum of cerium-doped yttrium silicate in Example 1 within the temperature range of 300K-500K, and Figure b shows the photoluminescence intensity versus temperature fitting graph of cerium-doped yttrium silicate in Example 1.

[0074] from Figure 4 It can be seen that within the temperature range of 300K-500K, the photoluminescence intensity of the emission peak of the cerium-doped yttrium silicate prepared in this invention gradually decreases with increasing temperature, which is a normal linear phenomenon. This is due to the thermal quenching phenomenon caused by the intensified electron-phonon coupling at high temperatures. Referring to the photoluminescence intensity versus temperature fitting graph in Figure b, the thermal ionization energy of the cerium-doped yttrium silicate prepared in this invention is 249.37 meV, which is higher than that of currently commercially available (Lu,Y)₂SiO₅:Ce (111.5 meV), Gd₂O₂S:Pr (221 meV), and Gd₃Ga₃Al₂O₅. 12 The Ce (206 meV) values ​​are all higher, which means that the thermal stability of the cerium-doped yttrium silicate of this invention is stronger than all of them.

[0075] Figure 5 Figure a shows an uncut photograph of the composite scintillator film of Application Example 1 and a photograph under ultraviolet light irradiation. Figure b shows a photograph of the composite scintillator film of Application Example 1 under ultraviolet light irradiation at a wavelength of 365 nm. Figure 6 Figure a shows the cut image of the composite scintillator film of Application Example 1 and the image under ultraviolet light irradiation. Figure b shows the cut image of the composite scintillator film of Application Example 1 and the image under ultraviolet light irradiation at a wavelength of 365 nm.

[0076] Figure 5 In Example 1, the uncut size of the composite scintillator film is 150 × 100 mm. Figure 6 In Application Example 1, the size of the composite scintillator film after cutting is 148 × 96 mm. Both the uncut and cut composite scintillator films in Application Example 1 emit dazzling blue light under ultraviolet light irradiation at a wavelength of 365 nm, indicating that arbitrary cutting of the composite scintillator film does not cause the luminescence failure of the composite scintillator film.

[0077] Figure 7 The image shows the X-ray lead plate edge resolution analysis of the composite scintillator thin film used in Example 1.

[0078] from Figure 7It is known that, based on the limiting spatial resolution (MTF=0.2) of the composite scintillator film, the X-ray imaging resolution of the composite scintillator film in Example 1 can reach 11.64 lp / mm, that is, a resolution of 1 / 11.64 mm. Considering that the resolution required by medical imaging CT equipment is greater than 3 lp / mm, it can be seen that the composite scintillator film prepared by this invention meets the requirements of medical imaging.

[0079] Figure 8 The images shown are X-ray images of the composite scintillator thin film used in Example 1. Figure a is a picture of the chip itself, and Figure b is an X-ray image of the chip using the composite scintillator thin film used in Example 1.

[0080] from Figure 8 As can be seen, when the composite scintillator film of the present invention is used for X-ray imaging of the chip, the surface and internal structure of the chip can be clearly observed, indicating that the composite scintillator film of the present invention has excellent X-ray imaging function and can serve medical imaging and security inspection.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing cerium-doped yttrium silicate lithium, characterized in that, Includes the following steps: S1. Mix Li2CO3, Y2O3, SiO2 and CeF3, and perform the first sintering to obtain the initial sintered powder; S2. The initial sintered powder is sintered a second time to obtain cerium-doped lithium yttrium silicate (LiYSiO4). In step S1, the temperature of the first sintering is 600-800℃; In step S2, the temperature of the second sintering is 1000-1200℃.

2. The method for preparing cerium-doped yttrium silicate as described in claim 1, characterized in that, Includes at least one of the following (1)-(3): (1) The mass ratio of SiO2 to CeF3 is 1:(0.01-0.1); (2) The mass ratio of SiO2 to Y2O3 is 1:(1.70-2.40); (3) The mass ratio of SiO2 to Li2CO3 is 1:(0.50-0.75).

3. The method for preparing cerium-doped yttrium silicate as described in claim 1, characterized in that, The mass ratio of SiO2 to CeF3 is 1:(0.03-0.08).

4. The method for preparing cerium-doped yttrium silicate as described in claim 1, characterized in that, Includes at least one of the following (1)-(6): (1) The first sintering time is 4-8 hours; (2) The gas atmosphere of the first sintering includes reducing gas; (3) The second sintering time is 8-12 hours; (4) The gas atmosphere of the second sintering includes reducing gas; (5) After the first sintering, the process also includes cooling to room temperature; (6) After the second sintering, the process also includes cooling to room temperature.

5. A cerium-doped yttrium silicate lithium, characterized in that, It is prepared by any of the preparation methods described in claims 1-4.

6. The application of cerium-doped yttrium silicate as described in claim 5 in scintillator materials.

7. A composite scintillator thin film, characterized in that, Including thermoplastic polyurethane and cerium-doped yttrium silicate as described in claim 5.

8. The composite scintillator thin film as described in claim 7, characterized in that, The mass ratio of the thermoplastic polyurethane to cerium-doped yttrium silicate is 100:(10-50).

9. A method for preparing a composite scintillator thin film as described in any one of claims 7-8, characterized in that, Includes the following steps: A mixed solution is obtained by mixing thermoplastic polyurethane, cerium-doped yttrium lithium silicate and solvent, and then the solution is electrospun into a film to obtain a composite scintillator film.

10. The application of a composite scintillator thin film as described in any one of claims 7-8 in X-ray imaging.

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