Dysprosium and europium co-doped sodium fluoride magnesium photoluminescence material and co-precipitation preparation method thereof

Abstract

According to the dysprosium and europium co-doped sodium fluoride magnesium light-release material and the co-precipitation preparation method thereof, the preparation raw materials are simple and safe, the batch uniformity is good, the preparation cost is low, the applicability is wide, and a powder sample shows the characteristics of the good light-release material; the OSL signal of the NaMgF3: Dy, Eu material has higher sensitivity than that of the commercially available Al2O3: C (InLight dosimeter) in different integration times; the degradation rate of the OSL response of the NaMgF3: Dy, Eu material within 15 days after irradiation is lower than 3.03%, the degradation rate of the OSL response of the NaMgF3: Dy, Eu material within 30 days after irradiation is lower than 10.79%, and the performance reaches the international advanced level. The NaMgF3: Dy, Eu photoluminescence material prepared by the invention can solve the problem that most of OSL materials decline seriously at present, obtains the OSL sensitivity which is competitive with that of a commercially available Al2O3: C material, and provides a solid guarantee for the accuracy and sensitivity of the material applied to nuclear radiation dose monitoring and traceability.

Description

Technical Field

[0001] This invention belongs to the field of nuclear radiation monitoring technology, specifically relating to a dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material for measuring radioactivity levels and its co-precipitation preparation method. Background Technology

[0002] Optically stimulated luminescence (OSL) materials emit light signals upon exposure to ionizing radiation. Since the emitted light signal is proportional to the radiation dose, the radiation dose can be calculated from the measured luminescence intensity. Compared to thermoluminescent (TL) technology, which uses heating to excite light, OSL technology offers advantages such as high sensitivity, real-time online measurement, short data readout time, low power consumption, and repeatability, making it an upgraded technology for TL. OSL dosimetry materials are the core component of OSL measurement technology, and their performance directly determines the accuracy and reliability of dose measurement. However, for a long time, OSL dosimetry materials used for cumulative dose monitoring of personnel and the environment have relied on imports.

[0003] Currently, only two commercially available OSL dosimetry materials are Al2O3:C and BeO. While these two materials perform excellently in OSL dosimetry applications, they still face many challenges in cost control and performance optimization. Exploring and developing OSL materials with ideal properties has become a common challenge for researchers. Ideal OSL materials should typically possess properties such as high sensitivity, low decay, easy bleaching, wide dynamic range, and near-tissue equivalence. Extensive research has been conducted on other types of OSL materials, but all have one or more dosimetric performance defects, failing to achieve a leap from experimental research to practical application.

[0004] Researchers both domestically and internationally have obtained promising dosimetric properties in various OSL materials based on sodium magnesium fluoride (NaMgF3). Camargo et al. synthesized NaMgF3:Tm material using a solid-state method, exhibiting a linear OSL response in the range of 0.05–100 Gy. However, the OSL response of this material decreased by approximately 13% within 60 hours after irradiation. Takebuchi et al. prepared NaMgF3:Tm material with an OSL dose response linear range of 1 mGy–10 Gy and a lower dose response limit; however, the TL emission curve showed a significant low-temperature peak at 80 °C, suggesting a severe OSL response decay. Le Masson et al., through comparative studies, found that the OSL sensitivity of NaMgF3:C material was 2.37 times that of Al2O3:C (Stillwater Sciences). However, this material also contained shallow trapping centers, leading to a strong OSL signal decay. Dotzler et al. prepared NaMgF3:Eu material using a high-temperature solid-state synthesis method, exhibiting high OSL sensitivity with a minimum detectable dose (MDD) of 0.13 μGy. However, even after process optimization, the OSL response of this material decreased by approximately 40% within 24 hours after irradiation. Zhang et al. synthesized NaMgF3:Eu material using a solid-state method, achieving an initial OSL sensitivity 1.65 times that of commercially available Al2O3:C (InLight dosimeter), with the OSL response decreasing by approximately 19.56% within 24 hours after irradiation. Guckan et al. prepared NaMgF3:Dy,Eu material using a hydrothermal method. This material not only possessed OSL sensitivity comparable to commercially available Al2O3:C (InLight dosimeter) but also exhibited a total OSL signal decrease of only approximately 6.6% within 5 days after irradiation. However, this performance was achieved by preheating the irradiated material to 100°C and holding it at that temperature for 10 seconds. The above studies indicate that although NaMgF3:Dy,Eu materials have shown promising OSL dosimetric properties, they still suffer from drawbacks such as OSL response decay dependence on pretreatment and the inability to simultaneously achieve high OSL sensitivity and stability. These limitations prevent them from fully leveraging the inherent advantages of OSL measurement technology in personal and environmental dosimetry applications. Therefore, further improvements are needed in the OSL decay and sensitivity properties of NaMgF3:Dy,Eu materials from the perspective of material synthesis and preparation. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] This invention proposes a dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence (OSL) material and its co-precipitation preparation method to solve the technical problems of severe degradation and poor practicality of OSL materials.

[0007] (II) Technical Solution

[0008] To address the aforementioned technical problems, this invention proposes a method for co-precipitating dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence (OSL) materials. This co-precipitation method includes the following steps:

[0009] S1. Weigh out sodium fluoride NaF, magnesium chloride hexahydrate MgCl2·6H2O, dysprosium oxide Dy2O3 and europium fluoride EuF3 powders according to the stoichiometric ratio of each chemical element in the chemical composition expression NaMgF3:Dy,Eu;

[0010] S2. Dissolve sodium fluoride (NaF) and magnesium chloride hexahydrate (MgCl2·6H2O) powders separately in ultrapure water to prepare sodium fluoride aqueous solution and magnesium chloride aqueous solution; mix the two aqueous solutions to allow them to fully contact and react.

[0011] S3. Further promote the precipitation reaction of ions in the mixed solution obtained in step S2 by oil bath heating and magnetic stirring;

[0012] S4. Separate the precipitate obtained in step S3 from the solution by filtration, and wash the precipitate multiple times with ultrapure water to remove residual ions and impurities;

[0013] S5. Take out the precipitate obtained after washing and dry it to obtain NaMgF3 precursor powder;

[0014] S6. The NaMgF3 precursor powder, dysprosium oxide (Dy2O3) and europium fluoride (EuF3) powders are placed in a crucible and thoroughly mixed. Then, the crucible is placed in a high-temperature tube furnace for heating. After heating, the crucible is removed, rapidly cooled, and poured into a mortar for grinding and sieving to obtain dysprosium-europium co-doped sodium magnesium fluoride NaMgF3:Dy,Eu optically stimulated luminescence material.

[0015] Further, in step S1, the mass ratio of sodium fluoride (NaF), magnesium chloride hexahydrate (MgCl2·6H2O), dysprosium oxide (Dy2O3), and europium fluoride (EuF3) powder is 12.0777:19.4919:0.1788:0.0401.

[0016] Furthermore, in step S1, the purity of both dysprosium oxide (Dy2O3) and europium fluoride (EuF3) is greater than or equal to 99.99%.

[0017] Furthermore, in step S3, the oil bath temperature is 85°C, the stirring speed of the magnetic stirrer is 700 rpm, and the reaction time is 12 h.

[0018] Furthermore, in step S5, drying is carried out at 85°C.

[0019] Furthermore, in step S6, the flow rate of nitrogen atmosphere in the tube furnace is 2 L / min, and the temperature is kept constant at 800℃ for 2 hours.

[0020] Furthermore, in step S6, the crucible is a platinum crucible, an alumina crucible, or a quartz crucible.

[0021] Furthermore, this invention also proposes a dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material prepared by the above-mentioned co-precipitation method. In this dysprosium-europium co-doped sodium magnesium fluoride NaMgF3:Dy,Eu optically stimulated luminescence material, the base material is sodium fluoride NaF and magnesium chloride hexahydrate MgCl2·6H2O, and the dopants are dysprosium oxide and europium fluoride.

[0022] Furthermore, the molar ratio of sodium fluoride (NaF) to magnesium chloride hexahydrate (MgCl2·6H2O) is 3:1.

[0023] Furthermore, the doping concentrations of dysprosium oxide and europium fluoride were 0.5 mol% and 0.2 mol% of sodium ions, respectively.

[0024] (III) Beneficial Effects

[0025] This invention proposes a dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence (OSL) material and its co-precipitation preparation method. The raw materials are simple and safe, with good batch uniformity, low preparation cost, and wide applicability. The powder sample exhibits good OSL characteristics. The OSL signal of the NaMgF3:Dy,Eu material shows higher sensitivity than that of commercially available Al2O3:C (InLight dosimeter) at different integration times. The OSL response of the NaMgF3:Dy,Eu material decays by less than 3.03% within 15 days after irradiation and by less than 10.79% within 30 days after irradiation, reaching international advanced levels. The NaMgF3:Dy,Eu optically stimulated luminescence material prepared by this invention can solve the problem of severe decay in most current OSL materials and achieves OSL sensitivity competitive with commercially available Al2O3:C materials, providing a solid guarantee for the accuracy and sensitivity of this material in nuclear radiation dose monitoring and source tracing. Attached Figure Description

[0026] Figure 1 A comparison of the optically stimulated luminescence decay curves of NaMgF3:Dy,Eu and commercially available Al2O3:C (InLight dosimeter) materials;

[0027] In the figure: the horizontal axis represents the readout time in seconds; the vertical axis represents the OSL intensity in counts / 0.1s; the red dots represent the OSL decay curves of NaMgF3:Dy,Eu; the green dots represent the OSL decay curves of the InLight dosimeter.

[0028] Figure 2 Optically stimulated luminescence response curves of NaMgF3:Dy,Eu relative to commercially available Al2O3:C (InLight dosimeter) material at different integration times;

[0029] In the figure: the horizontal axis represents the integration time of the OSL response, in seconds; the vertical axis represents the integrated OSL response relative to the InLight dosimeter.

[0030] Figure 3 The optically stimulated luminescence signal decay curve of NaMgF3:Dy,Eu;

[0031] In the figure: the horizontal axis represents the storage time of the material after irradiation, in days; the vertical axis represents the normalized relative intensity. Detailed Implementation

[0032] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0033] This embodiment proposes a dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material and its preparation method. The co-precipitation preparation method includes the following steps:

[0034] S1. According to the stoichiometric ratio of each chemical element in the chemical composition expression NaMgF3:Dy,Eu, weigh out 12.0777g of sodium fluoride NaF, 19.4919g of magnesium chloride hexahydrate MgCl2·6H2O, 0.1788g of dysprosium oxide Dy2O3 and 0.0401g of europium fluoride EuF3 powder; the purity of dysprosium oxide Dy2O3 and europium fluoride EuF3 are both greater than or equal to 99.99%;

[0035] S2. Dissolve sodium fluoride (NaF) and magnesium chloride hexahydrate (MgCl2·6H2O) powders in 350 mL and 200 mL of ultrapure water, respectively, to prepare sodium fluoride aqueous solution and magnesium chloride aqueous solution; mix the two aqueous solutions and allow them to fully contact and react.

[0036] S3. Further promote the precipitation reaction of ions in the mixed solution obtained in step S2 by oil bath heating and magnetic stirring; the oil bath temperature is 85℃, the magnetic stirring speed is 700rpm, and the reaction time is 12h.

[0037] S4. Separate the precipitate obtained in step S3 from the solution by filtration, and wash the precipitate five times with ultrapure water to remove residual ions and impurities;

[0038] S5. The precipitate obtained after washing is taken out and dried at 85°C to obtain NaMgF3 precursor powder;

[0039] S6. The NaMgF3 precursor powder, dysprosium oxide (Dy2O3), and europium fluoride (EuF3) powders were placed in a quartz crucible and thoroughly mixed. Then, the crucible was placed in a high-temperature tube furnace for heating. The flow rate of nitrogen atmosphere in the tube furnace was 2 L / min, and the temperature was kept constant at 800℃ for 2 h. After heating, the crucible was removed, rapidly cooled, and poured into a mortar for grinding and sieving to obtain dysprosium-europium co-doped sodium magnesium fluoride NaMgF3:Dy,Eu optically stimulated luminescence material.

[0040] In the dysprosium-europium co-doped sodium magnesium fluoride (NaMgF3:Dy,Eu) optically stimulated luminescence (OSL) material, the matrix consists of sodium fluoride (NaF) and magnesium chloride hexahydrate (MgCl2·6H2O), while the dopants are dysprosium oxide (NaF) and europium fluoride (EURB). The molar ratio of NaF to MgCl2·6H2O is 3:1. The doping concentrations of dysprosium oxide and europium fluoride are 0.5 mol% and 0.2 mol% of sodium ions, respectively.

[0041] use The OSL-DA-20C / D type readout instrument was used to measure the OSL signal of NaMgF3:Dy,Eu. For comparison, the OSL decay curves of commercially available Al2O3:C (InLight dosimeter) material were also measured. The OSL decay curves of the two materials are shown below. Figure 1 As shown, through Figure 1 It can be seen that the initial OSL sensitivity of the NaMgF3:Dy,Eu material is 1.33 times that of the InLight dosimeter. The integrated OSL responses of the two materials at 10 different integration times were statistically analyzed and normalized to the integrated OSL responses of the InLight dosimeter at the corresponding integration times. The results are as follows: Figure 2 As shown, through Figure 2 It can be seen that the NaMgF3:Dy,Eu material has a higher OSL sensitivity than the InLight dosimeter within the 90s integration time, and the total integrated OSL sensitivity can reach 2.34 times that of the InLight dosimeter.

[0042] The optically stimulated luminescence (OSL) signal decay curve of NaMgF3:Dy,Eu was tested, and the results are as follows: Figure 3 As shown, through Figure 3 It can be seen that the OSL response of NaMgF3:Dy,Eu material decays by less than 3.03% within 15 days after irradiation and by less than 10.79% within 30 days after irradiation (the NaMgF3:Dy,Eu material was not preheated during this performance test), that is, the OSL signal of NaMgF3:Dy,Eu remains relatively stable within 30 days.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for co-precipitating dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence materials, characterized in that, The coprecipitation preparation method includes the following steps: S1. Weigh out sodium fluoride NaF, magnesium chloride hexahydrate MgCl2·6H2O, dysprosium oxide Dy2O3 and europium fluoride EuF3 powders according to the stoichiometric ratio of each chemical element in the chemical composition expression NaMgF3:Dy,Eu; S2. Dissolve sodium fluoride (NaF) and magnesium chloride hexahydrate (MgCl2·6H2O) powders separately in ultrapure water to prepare sodium fluoride aqueous solution and magnesium chloride aqueous solution; mix the two aqueous solutions to allow them to fully contact and react. S3. Further promote the precipitation reaction of ions in the mixed solution obtained in step S2 by oil bath heating and magnetic stirring; S4. Separate the precipitate obtained in step S3 from the solution by filtration, and wash the precipitate multiple times with ultrapure water to remove residual ions and impurities; S5. Take out the precipitate obtained after washing and dry it to obtain NaMgF3 precursor powder; S6. The NaMgF3 precursor powder, dysprosium oxide (Dy2O3) and europium fluoride (EuF3) powders are placed in a crucible and thoroughly mixed. Then, the crucible is placed in a high-temperature tube furnace for heating. After heating, the crucible is removed, rapidly cooled, and poured into a mortar for grinding and sieving to obtain dysprosium-europium co-doped sodium magnesium fluoride NaMgF3:Dy,Eu optically stimulated luminescence material.

2. The method for co-precipitation preparation of dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 1, characterized in that, In step S1, the mass ratio of sodium fluoride (NaF), magnesium chloride hexahydrate (MgCl2·6H2O), dysprosium oxide (Dy2O3), and europium fluoride (EuF3) powder is 12.0777:19.4919:0.1788:0.0401.

3. The method for co-precipitation preparation of dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 1, characterized in that, In step S1, the purity of both dysprosium oxide (Dy2O3) and europium fluoride (EuF3) is greater than or equal to 99.99%.

4. The method for co-precipitation preparation of dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 1, characterized in that, In step S3, the oil bath temperature is 85℃, the magnetic stirring speed is 700rpm, and the reaction time is 12h.

5. The method for co-precipitation preparation of dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 1, characterized in that, In step S5, drying is carried out at 85°C.

6. The method for co-precipitation preparation of dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 1, characterized in that, In step S6, the flow rate of nitrogen atmosphere in the tube furnace is 2 L / min, and the temperature is kept constant at 800℃ for 2 hours.

7. The method for co-precipitation preparation of dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 1, characterized in that, In step S6, the crucible is a platinum crucible, an alumina crucible, or a quartz crucible.

8. A dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material prepared by the co-precipitation method according to any one of claims 1 to 7, characterized in that, In the dysprosium-europium co-doped sodium magnesium fluoride NaMgF3:Dy,Eu optically stimulated luminescence material, the base material is sodium fluoride NaF and magnesium chloride hexahydrate MgCl2·6H2O, and the dopants are dysprosium oxide and europium fluoride.

9. The dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 8, characterized in that, The molar ratio of sodium fluoride (NaF) to magnesium chloride hexahydrate (MgCl2·6H2O) is 3:

1.

10. The dysprosium-europium co-doped sodium magnesium fluoride optically stimulated luminescence material as described in claim 8, characterized in that, The doping concentrations of dysprosium oxide and europium fluoride were 0.5 mol% and 0.2 mol% of sodium ions, respectively.

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