Scintillation material and preparation method and application thereof

Abstract

The invention relates to the field of inorganic scintillating materials, in particular to a scintillating material and a preparation method and application thereof, the chemical general formula of the scintillating material is Ce alpha Gd < 3-alpha-beta Lu beta Ga gamma Al < 5-gamma > O < 12 >: xSiO2 and yMgO, 0.001 < = alpha < = 0.3, 0.005 < = beta < = 0.5, 1 < = gamma < = 3, 0.00001 < = x < = 0.0001, and 0.00001 < = y < = 0.002. A proper amount of Mg < 2 + > is doped in the scintillating material, part of Ce < 3 + > is promoted to be converted into Ce < 4 + >, the center of Ce < 4 + > provides a rapid radiation deexcitation channel, after conduction band electrons are captured, Ce < 3 + > in an excited state is formed, photons are immediately radiated, shallow electron traps are inhibited, the attenuation time of a scintillator is shortened, and afterglow is reduced. Meanwhile, a proper amount of Si < 4 + > is doped in the scintillation material, the radius of the Si < 4 + > is close to that of hexa-coordinated Al < 3 + >, the valence state of the Si < 4 + > is high, and the increase of cation vacancy and hole trap concentration caused by introduction of alkaline earth metal ions can be effectively inhibited, so that the attenuation is accelerated, the afterglow is reduced, the light yield is improved, and the garnet scintillation material has short afterglow and high luminous efficiency. The attenuation is fast; and the light yield is high.

Description

Technical Field

[0001] The present invention relates to the field of inorganic scintillation materials, and particularly to a scintillation material, a preparation method thereof, and an application thereof. Background Art

[0002] Scintillation materials can be used for the detection of high-energy rays such as α-rays, γ-rays, X-rays, and high-energy particles such as neutrons, and are widely used in the fields of nuclear medicine, high-energy physics, security inspection, oil logging, etc.

[0003] Scintillation materials are usually applied in the form of single crystals, ceramics, etc. Different application fields have different performance requirements for scintillation materials. However, for most application fields, it is desired that the scintillation material has as high a light yield as possible, as low an afterglow as possible, and as short an attenuation time as possible. Especially for nuclear medicine imaging devices such as X-ray computed tomography (X-CT), high light yield and low afterglow are crucial for imaging quality.

[0004] Alkaline earth metal ion doping can accelerate the attenuation of garnet scintillators. The principle is that charge compensation converts part of Ce 3+ to Ce 4+ . The Ce 4+ center provides a fast radiative de-excitation channel. After it captures the conduction band electrons, it forms excited-state Ce 3+ , and immediately radiates photons, which plays a key role in suppressing the slow component of the scintillation decay caused by shallow electron traps, making the attenuation time of the scintillation material shorter and the afterglow lower.

[0005] However, alkaline earth metal ions occupy the six-coordinate positions of Al 3+ in the garnet lattice, which leads to an increase in the concentration of cation vacancies and hole traps, quenching the energy transfer from Gd 3+ to Ce 3+ , and reducing the light output while suppressing the slow component of the scintillation emission.

[0006] Therefore, how to simultaneously shorten the afterglow of Ce:GGAG scintillation ceramics, accelerate the attenuation, and maintain a high light yield is a current research hotspot. Summary of the Invention

[0007] (1) Object of the Invention

[0008] The object of the present invention is to provide a scintillation material, a preparation method thereof, and an application thereof, which can shorten the afterglow, accelerate the attenuation, and maintain a high light yield.

[0009] (2) Technical Solution

[0010] To solve the above problems, the present invention provides a scintillation material, and the chemical general formula of the scintillation material is expressed as: Ce α Gd 3-α-β Lu β Ga γ Al 5-γ O 12 :xSiO2,yMgO, where 0.001 ≤ α ≤ 0.3, 0.005 ≤ β ≤ 0.5, 1 ≤ γ ≤ 3, 0.00001 ≤ x ≤ 0.0001, 0.00001 ≤ y ≤ 0.002.

[0011] On the other hand of the present invention, preferably, 0.00003 ≤ x ≤ 0.00005, 0.00005 ≤ y ≤ 0.00007.

[0012] On the other hand of the present invention, preferably, 0.01 ≤ α ≤ 0.05, 0.05 ≤ β ≤ 0.1, 1.5 ≤ γ ≤ 2.5.

[0013] On the other hand of the present invention, preferably, a method for preparing the scintillation material as described above includes the following steps:

[0014] Step 100: Mix the raw materials for forming the scintillation material and dissolve them in a mixed acid solution to obtain a first solution, and the pH of the mixed acid solution is between 1 and 2;

[0015] Step 200: Add a mixed alkali solution to the first solution to obtain a second solution, and the pH value of the second solution is between 7.5 and 8.0;

[0016] Step 300: After reacting the second solution for a preset time, dry it to obtain a first reactant;

[0017] Step 400: After calcining the first reactant, press it under a pressure environment to obtain a second reactant;

[0018] Step 500: Sinter the second reactant to obtain a third reactant;

[0019] Step 600: Anneal the third reactant to obtain the scintillation material.

[0020] On the other hand of the present invention, preferably, the raw materials for forming the scintillation material include: CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2 and MgO.

[0021] On the other hand of the present invention, preferably, the calcining of the first reactant in step 400 includes:

[0022] The calcining temperature is 700 - 900 °C, and the calcining time is 2 - 5 h.

[0023] On the other hand of the present invention, preferably,

[0024] The pressing under a pressure environment in step 400 includes:

[0025] Performing dry pressing on the calcined first reactant, with a pressure of 8 - 10 MPa and a time of 2 - 4 min,

[0026] Performing cold isostatic pressing on the dry - pressed first reactant, with a pressure of 200 - 250 MPa and a time of 3 - 5 min.

[0027] On the other hand of the present invention, preferably, the sintering of the second reactant in step 500 includes:

[0028] Sintering the second reactant in an oxygen atmosphere, with a sintering temperature of 1600 - 1800 °C and a holding time of 3 - 5 h;

[0029] Performing hot isostatic pressing on the sintered second reactant, with a pressure of 150 - 220 MPa, a temperature of 1500 - 1750 °C, and a holding time of 3 - 5 h.

[0030] On the other hand of the present invention, preferably,

[0031] The annealing of the third reactant in step 600 includes:

[0032] The annealing temperature is 1000 - 1350 °C and the holding time is 10 - 30 h.

[0033] On the other hand of the present invention, preferably, the application of the scintillation material as described above or the scintillation material prepared by the preparation method as described above in the preparation of a scintillation detector, an X - ray computed tomography imaging device, and a positron emission tomography imaging device.

[0034] (III) Beneficial effects

[0035] The above - mentioned technical solution of the present invention has the following beneficial technical effects:

[0036] By doping an appropriate amount of Mg in the scintillation material of the present invention 2+ , promoting part of Ce 3+ to transform into Ce 4+ , the Ce 4+ center provides a fast radiative de - excitation channel. After it captures the conduction - band electrons, it forms an excited - state Ce 3+ , and immediately radiates photons, inhibits shallow electron traps, shortens the decay time of the scintillator, and reduces the afterglow. At the same time, by doping an appropriate amount of Si in the scintillation material 4+ , the Si 4+ radius and six - coordinated Al3+ Being close and having a high valence state can effectively inhibit the increase in the concentration of cation vacancies and hole traps caused by the introduction of alkaline earth metal ions. Thus, while accelerating the decay and reducing the afterglow, the light yield is increased, enabling the garnet scintillation material to possess excellent properties such as short afterglow, fast decay, and high light yield. Further, when 2+ Mg 4+ and 2+ Si 4+ are doped within the scope of this application, the light yield can be increased while accelerating the decay and reducing the afterglow. If the doping amounts of 2+ Mg 4+ and Description of the Drawings

[0037] Figure 1 is a flowchart of the preparation method according to an embodiment of the present invention. Detailed Embodiments

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the detailed embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following descriptions, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0039] Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "first", "second", and "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0041] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] Embodiment

[0043] A scintillation material, the chemical general formula of the scintillation material is expressed as: Ce α Gd 3-α-β Lu β Ga γ Al 5-γ O 12: xSiO2, yMgO, where 0.001 ≤ α ≤ 0.3, 0.005 ≤ β ≤ 0.5, 1 ≤ γ ≤ 3, 0.00001 ≤ x ≤ 0.0001, 0.00001 ≤ y ≤ 0.002;

[0044] Further, in this embodiment, 0.00003 ≤ x ≤ 0.00005, 0.00005 ≤ y ≤ 0.00007; 0.01 ≤ α ≤ 0.05, 0.05 ≤ β ≤ 0.1, 1.5 ≤ γ ≤ 2.5.

[0045] The specific form of the scintillation material is not limited herein. Optionally, it can be powder, ceramic or single crystal. Optionally, in this embodiment, the form of the scintillation material is ceramic.

[0046] Further, in this embodiment, the light yield of the scintillation material can reach more than 60,000, the afterglow can be as low as below 0.1% @ 20 ms, and the decay time can be shortened to below 100 ns.

[0047] In this embodiment, by doping an appropriate amount of Mg into the scintillation material 2+ , promoting part of Ce 3+ to transform into Ce 4+ , the Ce 4+ center provides a fast radiative de-excitation channel. After capturing the conduction band electrons, it forms excited Ce 3+ , and immediately radiates photons, inhibits shallow electron traps, shortens the decay time of the scintillator, and reduces the afterglow. At the same time, by doping an appropriate amount of Si into the scintillation material 4+ , the radius of Si 4+ is close to that of six-coordinated Al 3+ and has a high valence state, which can effectively inhibit the increase in the concentration of cation vacancies and hole traps caused by the introduction of alkaline earth metal ions. Thus, while accelerating the decay and reducing the afterglow, the light yield is improved, enabling the garnet scintillation material to have excellent properties of short afterglow, fast decay and high light yield. Further, when the doping amounts of Mg 2+ and Si 4+ are within the scope of this application, the light yield can be improved while accelerating the decay and reducing the afterglow. If the doping amounts of Mg 2+ and Si 4+ are lower than the scope of this application, there is no improvement effect, while if the doping amounts of Mg 2+ and Si 4+ are higher than the scope of this application, a secondary phase will be formed, affecting the transparency and optical properties of the material.

[0048] A method for preparing the scintillation material as described above includes the following steps:

[0049] Step 100: Mix the raw materials for forming the scintillation material and dissolve them in a mixed acid solution to obtain a first solution. The specific content of the raw materials for forming the scintillation material is not limited here. Optionally, in this embodiment, the raw materials for forming the scintillation material include: CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO. The ratio of the raw materials is not limited here. Powders can be accurately weighed and mixed according to the selected α, β, γ, x, and y, according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 :ySiO2. The purity and particle size of CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO are not limited here either. Optionally, it can be 4N purity or above. The pH of the mixed acid solution is 1-2. Here, the first solution is a salt solution containing seven ions of Al 3+ 、Ga 3+ 、Gd 3+ 、Lu 3+ 、Ce 3+ 、Si 4+ and Mg 2+ . The specific content of the mixed acid solution is not limited here. Optionally, in this embodiment, the mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid;

[0050] Step 200: Add a mixed alkali solution to the first solution to obtain a second solution, and the pH value of the second solution is between 7.5 and 8.0. Here, the way of adding the mixed alkali solution is by dropping. The specific content of the mixed alkali solution is not limited here. Optionally, in this embodiment, the mixed alkali solution includes a mixed solution of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8-9;

[0051] Step 300: After reacting the second solution for a preset time, dry it to obtain a first reactant. The specific drying method is not limited here. Optionally, in this embodiment, the second solution is centrifuged and dried to obtain the first reactant. The specific content of the preset reaction time of the second solution is not limited here. Optionally, the preset reaction time of the second solution here is 3-5h;

[0052] Step 400: After calcining the first reactant, press it under a pressure environment to obtain a second reactant; the specific content of calcination is not limited here. Optionally, in this embodiment, the calcination includes: the calcination temperature is 700 - 900 °C, and the calcination time is 2 - 5 h; the specific content of pressing under a pressure environment is not limited here either. Optionally, in this embodiment, pressing under a pressure environment includes: subjecting the calcined first reactant to dry pressing, with a pressure of 8 - 10 MPa and a time of 2 - 4 min, and then subjecting the dry-pressed first reactant to cold isostatic pressing, with a pressure of 200 - 250 MPa and a time of 3 - 5 min;

[0053] Step 500: Sinter the second reactant to obtain a third reactant; the specific content of sintering is not limited here either. Optionally, in this embodiment, the sintering includes: sintering the second reactant in an oxygen atmosphere, with a sintering temperature of 1600 - 1800 °C and a holding time of 3 - 5 h; subjecting the sintered second reactant to hot isostatic pressing, with a pressure of 150 - 220 MPa, a temperature of 1500 - 1750 °C, and a holding time of 3 - 5 h;

[0054] Step 600: Anneal the third reactant to obtain a scintillation material; the specific content of annealing is not limited here either. Optionally, in this embodiment, the annealing includes: the annealing temperature is 1000 - 1350 °C, and the holding time is 10 - 30 h.

[0055] The scintillation material obtained by the preparation method of this embodiment has good scintillation performance, and its comprehensive performance is significantly better than that of conventional scintillation materials without doping silicon and magnesium ions. The grain uniformity is significantly better than that of undoped scintillation materials, and at the same time, the production yield of the preparation is significantly improved.

[0056] Application of the scintillation material as described above or the scintillation material prepared by the preparation method as described above in the preparation of scintillation detectors, X-ray computed tomography imagers, and positron emission tomography imagers.

[0057] In the following examples and comparative examples, the light yield and energy resolution are obtained by multi-channel energy spectrum detection based on a 137Cs radiation source, and the decay time is obtained by X-ray fluorescence spectroscopy detection.

[0058] Comparative Example 1:

[0059] Ce 0.35 Gd 2.499 Lu 0.6 Ga4AlO 12 ; Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, according to the general formula Ce α Gd3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : Precisely weigh and mix the powders of ySiO2. Dissolve the raw material powders in a mixed acid solution with a certain concentration to obtain a salt solution containing seven ions of Al 3+ , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+ at the same time. Dropwise add a mixed alkali solution to the salt solution to adjust the pH value to 7.5 - 8.0 to obtain a precursor mother liquor. The mother liquor is centrifuged and dried to obtain nano-powders. Put the precursor into a muffle furnace and pre-burn it at 700 - 900 °C for 2 - 5 h to obtain GGAG garnet powders with high light yield doped with silicon and magnesium ions. Dry press the powders at 8 - 10 MPa for 3 min, and then further perform cold isostatic pressing with a pressure of 200 - 250 MPa for 3 - 5 min to obtain a ceramic green body. Adopt a two-step sintering process for the green body. First, sinter it in an oxygen atmosphere with a sintering temperature of 1600 - 1800 °C and a holding time of 3 - 5 h, and then perform hot isostatic pressing treatment with a pressure of 150 - 220 MPa, a sintering temperature of 1500 - 1750 °C, and a holding time of 3 - 5 h to obtain a ceramic sample. Anneal the ceramic sample by placing it in a muffle furnace and holding it at 1000 - 1350 °C for 10 - 30 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0060] For Comparative Examples 2 to 4, except for the different raw material ratios, the other operations are the same as those in Comparative Example 1.

[0061] Example 1:

[0062] Ce 0.001 Gd 2.994 Lu 0.005 GaAl4O 12 :0.00001SiO2,0.00001MgO

[0063] Use high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, MgO powders. According to the selected α, β, γ, x and y, according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12Precisely weigh and mix the powders according to the ratio of ySiO₂. Dissolve the raw material powders in a mixed acid solution, which includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1; obtain a first solution containing seven ions of Al 3+ 、Ga 3+ 、Gd 3+ 、Lu 3+ 、Ce 3+ 、Si 4+ and Mg 2+ Dropwise add a mixed alkali solution to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8. Adjust the pH value to 7.5 to obtain a second solution. After the second solution reacts for a preset time of 3 h, the second solution is centrifuged and dried to obtain a first reactant. Put the first reactant into a muffle furnace and pre-burn it at 700 °C for 5 h to obtain garnet powder with high light yield doped with silicon and magnesium ions. Press the powder at 8 MPa for 4 min by dry pressing, and then perform further cold isostatic pressing with a pressure of 200 MPa for 5 min to obtain a second reactant. Use a two-step sintering process for the second reactant. First, sinter it in an oxygen atmosphere at a sintering temperature of 1600 °C for a holding time of 5 h, and then perform hot isostatic pressing treatment with a pressure of 150 MPa, a sintering temperature of 1500 °C, and a holding time of 5 h to obtain a third reactant. Anneal the third reactant by placing it in a muffle furnace and holding it at 1000 °C for 30 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0064] Example 2

[0065] Ce 0.005 Gd 2.975 Lu 0.02 Ga 1.2 Al 3.8 O 12 :0.00002SiO₂,0.00008MgO

[0066] Use high-purity CeO₂, Gd₂O₃, Ga₂O₃, Lu₂O₃, Al₂O₃, SiO₂, and MgO powders. According to the selected α, β, γ, x, and y, according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 :ySiO₂, precisely weigh and mix the powders. Dissolve the raw material powders in a mixed acid solution, which includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 2; obtain a solution containing Al 3+ 、Ga 3+ 、Gd 3+, Lu 3+ , Ce 3+ , Si 4+ and Mg 2+ A first solution containing seven ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 9. The pH value is adjusted to 8 to obtain a second solution. After the second solution reacts for a preset time of 5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-fired at 900 °C for 2 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 10 MPa for 2 min and then further cold isostatically pressed at a pressure of 250 MPa for 3 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1800 °C for a holding time of 3 h, and then hot isostatically pressed at a pressure of 220 MPa and a sintering temperature of 1750 °C for 3 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1350 °C for 10 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0067] Example 3

[0068] Ce 0.01 Gd 2.94 Lu 0.05 Ga 1.5 Al 3.5 O 12 : 0.00003 SiO2, 0.00005 MgO

[0069] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, accurately weigh and mix the powders according to the selected α, β, γ, x, and y, and in accordance with the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2. Dissolve the raw material powders in a mixed acid solution, which includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.5; obtain a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+A first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.5. The pH value is adjusted to 7.7 to obtain a second solution. After the second solution reacts for a preset time of 3.5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-calcined at 800 °C for 3 h to obtain a garnet powder with high light yield doped with silicon and magnesium ions. The powder is dry-pressed at 9 MPa for 3 min, and then further cold isostatically pressed at a pressure of 220 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1700 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 200 MPa and a sintering temperature of 1650 °C for 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1200 °C for 20 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0070] Example 4

[0071] Ce 0.015 Gd 2.977 Lu 0.08 Ga2Al3O 12 :0.00004SiO2,0.00006MgO

[0072] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, MgO powders, according to the selected α, β, γ, x and y, in accordance with the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 :ySiO2, the powders are accurately weighed and mixed. The raw material powders are dissolved in a mixed acid solution, and the mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.3; obtaining a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+The first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.8. The pH value is adjusted to 7.8 to obtain the second solution. After the second solution reacts for a preset time of 4 h, the second solution is centrifuged and dried to obtain the first reactant. The first reactant is placed in a muffle furnace and pre-fired at 850 °C for 3 h to obtain garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 8.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 210 MPa for 4 min to obtain the second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1750 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 210 MPa and a sintering temperature of 1550 °C for 4 h to obtain the third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1100 °C for 25 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0073] Example 5

[0074] Ce 0.05 Gd 2.85 Lu 0.1 Ga 2.5 Al 2.5 O 12 : 0.00005 SiO2, 0.00007 MgO

[0075] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, powders are accurately weighed and mixed according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2. The raw material powders are dissolved in a mixed acid solution. The mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.5; obtaining a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+The first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.2. The pH value is adjusted to 8 to obtain the second solution. After the second solution reacts for a preset time of 3.5 h, the second solution is centrifuged and dried to obtain the first reactant. The first reactant is placed in a muffle furnace and pre-fired at 700 °C for 3 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 9.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 240 MPa for 4 min to obtain the second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1800 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 220 MPa and a sintering temperature of 1550 °C for 4 h to obtain the third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1100 °C for 25 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0076] Example 6

[0077] Ce 0.1 Gd 2.6 Lu 0.3 Ga 2.7 Al 2.3 O 12 : 0.00007 SiO2, 0.00009 MgO

[0078] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, accurately weigh and mix the powders according to the selected α, β, γ, x, and y, and according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2 for the ratio. Dissolve the raw material powders in a mixed acid solution. The mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.8; obtain a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+The first solution of seven ions, a mixed alkali solution is added dropwise to the first solution, the mixed alkali solution includes a mixed solution of ammonia water and ammonium bicarbonate, the pH of the mixed alkali is 8.1, and the pH value is adjusted to 7.9 to obtain a second solution. After the second solution reacts for a preset time of 4.5 hours, the second solution is centrifuged and dried to obtain the first reactant. The first reactant is placed in a muffle furnace and pre-calcined at 750°C for 4.5 hours to obtain a garnet powder doped with silicon and magnesium ions with high light yield. The powder is dry pressed at 9.5MPa for 3 minutes, and then further cold isostatically pressed at a pressure of 230MPa for 4 minutes to obtain a second reactant. The second reactant is subjected to a two-step sintering process, first sintered in an oxygen atmosphere at a sintering temperature of 1800°C for 4 hours, and then hot isostatically pressed at a pressure of 220MPa, a sintering temperature of 1550°C, and a heat preservation time of 4 hours to obtain a third reactant. The third reactant is subjected to annealing treatment, placed in a muffle furnace, and kept at 1100° C. for 25 hours to obtain a garnet scintillating material doped with silicon and magnesium ions.

[0079] Example 7

[0080] Ce 0.3 G 2.2 Lu 0.5 Ga3Al2O 12 :0.0001SiO2,0.0001MgO

[0081] Use high purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, MgO powder, select α, β, γ, x and y, according to the general formula Ce α G 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 :ySiO2 powders are accurately weighed and mixed. The raw material powders are dissolved in a mixed acid solution, the mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.6; a mixture containing Al 3 + , Ga 3+ , Gd 3+ 、Lu 3+ 、Ce 3+ 、Si 4+ and Mg 2+The first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.3. The pH value is adjusted to 7.5 to obtain a second solution. After the second solution reacts for a preset time of 4.5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-fired at 880 °C for 3 h to obtain a garnet powder with high light yield doped with silicon and magnesium ions. The powder is dry-pressed at 8.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 235 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1700 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 170 MPa and a sintering temperature of 1600 °C for 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1200 °C for 27 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0082] Example 8

[0083] Ce 0.005 Gd 2.695 Lu 0.3 Ga 1.3 Al 3.2 O 12 : 0.00002 SiO2, 0.00008 MgO

[0084] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, the powders are accurately weighed and mixed according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2 ratio. The raw material powders are dissolved in a mixed acid solution. The mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.7; obtaining a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+A first solution of seven ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.5. The pH value is adjusted to 7.9 to obtain a second solution. After the second solution reacts for a preset time of 4.5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-burned at 750 °C for 3 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 9.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 230 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1750 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 220 MPa and a sintering temperature of 1650 °C for 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1150 °C for 23 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0085] Example 9

[0086] Ce 0.03 Gd 2.9 Lu 0.07 Ga 1.8 Al 3.2 O 12 : 0.00005 SiO2, 0.00005 MgO

[0087] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, the powders are accurately weighed and mixed according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2. The raw material powders are dissolved in a mixed acid solution, which includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.3; obtaining a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+A first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.6. The pH value is adjusted to 7.9 to obtain a second solution. After the second solution reacts for a preset time of 3.5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-calcined at 720 °C for 3 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 9.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 240 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1800 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 225 MPa and a sintering temperature of 1550 °C for 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1100 °C for 18 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0088] Example 10

[0089] Ce 0.2 Gd 2.79 Lu 0.01 Ga 2.6 Al 2.4 O 12 : 0.00008 SiO2, 0.00002 MgO

[0090] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, powders are accurately weighed and mixed according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2 ratio. The raw material powders are dissolved in a mixed acid solution, and the mixed acid solution includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.5; obtaining a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+The first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.9. The pH value is adjusted to 7.9 to obtain a second solution. After the second solution reacts for a preset time of 5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-burned at 750 °C for 3 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 9.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 240 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1700 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 220 MPa, a sintering temperature of 1700 °C, and a holding time of 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1300 °C for 15 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0091] Example 11

[0092] Ce 0.2 Gd 2.79 Lu 0.01 Ga 2.6 Al 2.4 O 12 : 0.00006 SiO2, 0.001 MgO

[0093] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, powders are accurately weighed and mixed according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2. The raw material powders are dissolved in a mixed acid solution, which includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.5; to obtain a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+The first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.9. The pH value is adjusted to 7.9 to obtain a second solution. After the second solution reacts for a preset time of 5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-calcined at 750 °C for 3 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 9.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 240 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1700 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 220 MPa, a sintering temperature of 1700 °C, and a holding time of 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1300 °C for 15 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0094] Example 12

[0095] Ce 0.2 Gd 2.79 Lu 0.01 Ga 2.6 Al 2.4 O 12 : 0.00006 SiO2, 0.002 MgO

[0096] Using high-purity CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2, and MgO powders, according to the selected α, β, γ, x, and y, powders are accurately weighed and mixed according to the general formula Ce α Gd 3-α-β-γ Lu β Y γ Ga x Al 5-x O 12 : ySiO2. The raw material powders are dissolved in a mixed acid solution, which includes a mixed solution of hydrochloric acid and nitric acid, and the pH of the mixed acid solution is 1.5; obtaining a solution containing Al 3 + , Ga 3+ , Gd 3+ , Lu 3+ , Ce 3+ , Si 4+ and Mg 2+The first solution of seven kinds of ions. A mixed alkali solution is added dropwise to the first solution. The mixed alkali solution includes a mixture of ammonia water and ammonium bicarbonate, and the pH of the mixed alkali is 8.9. The pH value is adjusted to 7.9 to obtain a second solution. After the second solution reacts for a preset time of 5 h, the second solution is centrifuged and dried to obtain a first reactant. The first reactant is placed in a muffle furnace and pre-calcined at 750 °C for 3 h to obtain a garnet powder doped with silicon and magnesium ions with a high light yield. The powder is dry-pressed at 9.5 MPa for 3 min, and then further cold isostatically pressed at a pressure of 240 MPa for 4 min to obtain a second reactant. The second reactant is subjected to a two-step sintering process. First, it is sintered in an oxygen atmosphere at a sintering temperature of 1700 °C for a holding time of 4 h, and then hot isostatically pressed at a pressure of 220 MPa, a sintering temperature of 1700 °C, and a holding time of 4 h to obtain a third reactant. The third reactant is annealed by placing it in a muffle furnace and holding it at 1300 °C for 15 h to obtain a garnet scintillation material doped with silicon and magnesium ions.

[0097] The test results of the chemical composition, light yield, afterglow, and decay time of the scintillation materials in Examples 1 to 12 and Comparative Examples 1 to 4 are shown in Table 1.

[0098] Table 1 Test results of the scintillation materials in Examples 1 to 12 and Comparative Examples 1 to 4

[0099]

[0100]

[0101] In summary, the scintillation material obtained in the present invention is doped with an appropriate amount of Mg 2+ , which promotes the conversion of part of Ce 3+ to Ce 4 + . The Ce 4+ center provides a fast radiative de-excitation channel. After capturing the conduction band electrons, it forms an excited Ce 3+ , and immediately radiates photons, inhibits shallow electron traps, shortens the decay time of the scintillator, and reduces the afterglow. At the same time, an appropriate amount of Si 4+ is doped in the scintillation material. The radius of Si 4+ is close to that of six-coordinated Al 3+ and has a high valence state, which can effectively inhibit the increase in the concentration of cation vacancies and hole traps caused by the introduction of alkaline earth metal ions. Therefore, while accelerating the decay and reducing the afterglow, the light yield is improved, enabling the garnet scintillation material to have excellent properties of short afterglow, fast decay, and high light yield.

[0102] It should be understood that the above specific embodiments of the present invention are only for illustrative explanation or interpretation of the principles of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0103] The present invention has been described above with reference to the embodiments of the present invention. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should fall within the scope of the present invention.

[0104] Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and alterations can be made to the embodiments of the present invention without departing from the spirit and scope of the present invention.

[0105] Obviously, the above embodiments are only examples given for clear illustration and not limitations to the embodiments. For those of ordinary skill in the art, other different forms of changes or variations can be made on the basis of the above description. It is not necessary and impossible to enumerate all the embodiments here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A scintillating material, characterized in that, The chemical general formula of the scintillation material is expressed as: Ce α Gd 3-α-β Lu β Ga γ Al 5-γ O 12 :xSiO2,yMgO, where 0.001 ≤ α ≤ 0.3, 0.005 ≤ β ≤ 0.5, 1 ≤ γ ≤ 3, 0.00001 ≤ x ≤ 0.0001, 0.00001 ≤ y ≤ 0.

002.

2. The scintillating material according to claim 1, wherein 0.00003 ≤ x ≤ 0.00005, 0.00005 ≤ y ≤ 0.00007.

3. The scintillating material according to claim 1, wherein , 0.01 ≤ α ≤ 0.05, 0.05 ≤ β ≤ 0.1, 1.5 ≤ γ ≤ 2.

5.

4. A method for preparing a scintillation material as described in any one of claims 1-3, characterized in that, It includes the following steps: Step 100: Mix the raw materials for forming the scintillation material and dissolve them in a mixed acid solution to obtain a first solution, and the pH of the mixed acid solution is between 1 and 2; Step 200: Add a mixed alkali solution to the first solution to obtain a second solution, and the pH value of the second solution is between 7.5 and 8.0; Step 300: After reacting the second solution for a preset time, dry it to obtain a first reactant; Step 400: After calcining the first reactant, press it under a pressure environment to obtain a second reactant; Step 500: Sinter the second reactant to obtain a third reactant; Step 600: Anneal the third reactant to obtain a scintillation material.

5. The preparation method according to claim 4, characterized in that: The raw materials for forming the scintillation material include: CeO2, Gd2O3, Ga2O3, Lu2O3, Al2O3, SiO2 and MgO.

6. According to the preparation method described in claim 4, characterized in that, In step 400, the calcining of the first reactant includes: The calcining temperature is 700 - 900 °C, and the calcining time is 2 - 5 h.

7. According to the preparation method described in claim 4, characterized in that, In step 400, the pressing under a pressure environment includes: Perform dry pressing on the calcined first reactant, the pressure is 8 - 10 MPa, and the time is 2 - 4 min, Perform cold isostatic pressing on the first reactant after dry pressing, the pressure is 200 - 250 MPa, and the time is 3 - 5 min.

8. According to the preparation method described in claim 4, characterized in that, In step 500, the sintering of the second reactant includes: Sinter the second reactant in an oxygen atmosphere, the sintering temperature is 1600 - 1800 °C, and the holding time is 3 - 5 h; Perform hot isostatic pressing on the second reactant after sintering, the pressure is 150 - 220 MPa, the temperature is 1500 - 1750 °C, and the holding time is 3 - 5 h.

9. According to the preparation method described in claim 4, characterized in that, In step 600, the annealing of the third reactant includes: The annealing temperature is 1000 - 1350 °C, and the holding time is 10 - 30 h.

10. The application of the scintillation material described in any one of claims 1 - 3 or the scintillation material prepared by the preparation method described in any one of claims 4 - 9 in the preparation of a scintillation detector, an X - ray computed tomography imaging device, and a positron emission tomography imaging device.

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