Rare earth ion doped gallate stress fluorescent powder and preparation method thereof

Abstract

The invention belongs to the technical field of stress luminescent materials, and provides rare earth ion doped gallate stress fluorescent powder and a preparation method thereof, the chemical general formula of the fluorescent powder is SrLa1-xGaO4: xTb < 3 + >, x represents the mole fraction, and x is more than or equal to 0.005 and less than or equal to 0.9; the preparation method comprises the following steps: 1) proportioning SrCO3, La2O3, Ga2O3 and Tb4O7 according to a chemical formula, adding H3BO3 as a fluxing agent, grinding, drying, firing, and grinding again to obtain the fluorescent powder; 2) mixing PDMS with a curing agent to obtain a PDMS mixed solution; and (3) sequentially pouring the fluorescent powder and PDMS mixed solution according to the formula ratio into a mold, standing, drying and demolding to obtain the stress luminescent material. The stress luminescence intensity is adjusted by regulating and controlling the concentration of Tb < 3 + >, green stress luminescence is achieved, pre-radiation is not needed, and the stress luminescence material is excellent in performance; the material is prepared by adopting a high-temperature solid-phase method, the preparation process is simple, the conditions are easy to control, and the preparation process is environment-friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of stress luminescent materials, and in particular to a rare earth ion-doped gallate stress phosphor and a preparation method thereof. Background Art

[0002] Stress luminescence (ML) refers to the phenomenon in which a material produces light when subjected to mechanical stimulation (such as friction, compression, stretching, or fracture). Mechanical energy is ubiquitous in our lives, so ML materials play an important role in structural health monitoring, flexible electronics and wearable devices, anti-counterfeiting and encryption, and stress sensing. To date, ML materials have mostly been concentrated in sulfide and aluminate systems. However, sulfide and aluminate are very unstable, and aluminate requires a relatively high calcination temperature. Therefore, how to obtain a new type of ML material with simple synthesis conditions, stress luminescence, and high stability is one of the problems that need to be solved in this field.

[0003] Most existing stress luminescent materials are inorganic stress luminescent materials, which have low luminescence intensity, insufficient sensitivity, narrow spectral range, poor environmental stability and poor repeatability. Moreover, the research on ML materials is still in its initial stage, and the ML performance of most materials does not meet the requirements of practical applications. Therefore, further exploration of excellent ML materials is needed.

[0004] Research has found that gallates (such as Y3GaO6, SrLaGaO4, and BaSrGa4O8) not only possess charge carrier traps but also exhibit lower synthesis temperatures and higher stability, resulting in superior physical and chemical stability compared to other luminescent hosts. Based on this, olivine-type SrLaGaO4 is a potential new host for efficient stress-induced luminescence. It is prepared using a high-temperature solid-phase method, which is simple and environmentally friendly, without the need for an inert or reducing atmosphere. Furthermore, this gallate is modified by doping to introduce luminescent centers, enabling it to produce green luminescence under mechanical stimulation without pre-excitation, demonstrating excellent stress-induced luminescence performance. Summary of the Invention

[0005] The present invention aims to provide a rare earth ion doped gallate stress phosphor and its preparation method, by regulating Tb 3+ The concentration of La was used to adjust the stress luminescence intensity, and Tb was used to replace La. 3+ The surrounding crystal field environment realizes visible stress luminescence; and the preparation method of this material is the traditional high-temperature solid-phase method, which has a simple preparation process, low equipment requirements, easy-to-control conditions, low cost, and no toxic or harmful substances are produced during the preparation process, which meets the requirements of green environmental protection.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A rare earth ion doped gallate stress phosphor, the chemical formula of the stress phosphor is: SrLa 1- x GaO4:xTb 3+ , where 0.005≤x≤0.09.

[0008] The method for preparing the rare earth ion-doped gallate stress phosphor comprises the following steps:

[0009] S1. Weighing raw materials according to the stoichiometric ratio of each component and adding them into an agate mortar to obtain an initial mixed raw material;

[0010] S2. Add alcohol to the agate mortar containing the mixed raw materials for grinding, and pour the ground mixture into an alumina crucible;

[0011] S3. Place the alumina crucible containing the mixture into a muffle furnace, and prepare the desired stress phosphor using a high-temperature solid-phase method.

[0012] Furthermore, in S1, the raw materials weighed are SrCO3, La2O3, Ga2O3, and Tb4O7, and H3BO3 is added as a flux. The purity of SrCO3 is 99.95%, and the purity of the remaining raw materials is 99.99%.

[0013] Furthermore, in S2, the time for adding alcohol for grinding is 30 minutes.

[0014] Furthermore, in S3, the alumina crucible containing the mixture is heated to 1300°C at 5°C / min in a muffle furnace for sintering and kept warm for 4 hours; then the temperature is lowered to 1000°C at 5°C / min, and then naturally cooled to room temperature. Finally, the sample in the crucible is poured into an agate mortar and ground to obtain a stress phosphor.

[0015] The beneficial effects of the technical solution are:

[0016] 1. The stress phosphor provided by the present invention has photoluminescence emission when irradiated at 274nm, and after mixing with PDMS colloid, a stress luminescent composite film is obtained. The film has strong green stress luminescence under mechanical stimulation without pre-excitation; and by regulating Tb 3+ The concentration of La was used to adjust the stress luminescence intensity, and Tb was used to replace La. 3+ The surrounding crystal field environment, Tb 3+ As a luminescent center, it achieves visible stress luminescence, which is beneficial for its application in anti-counterfeiting, structural health detection, sensors and other fields;

[0017] 2. The stress phosphor preparation method of the present invention adopts high-purity raw material powder, which is particularly suitable for preparing high-purity phosphor. The obtained product has good stability and moisture-proof performance. It adopts conventional high-temperature solid-phase reaction method for preparation, which has the advantages of simple process, low equipment cost, easy control of operating conditions, and cost-effectiveness. In addition, the entire preparation process does not emit toxic and harmful substances, and meets green environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a scanning electron microscope photograph of the stress phosphor prepared in Example 5 of the present invention;

[0019] Figure 2 This is the XRD test curve of the phase of the stress phosphors prepared in Examples 1 to 6 of the present invention;

[0020] Figure 3 This is the photoluminescence spectrum of the stress phosphor prepared in Example 5 of the present invention;

[0021] Figure 4 This is the stress luminescence spectrum of the stress phosphor prepared in Example 5 of the present invention;

[0022] Figure 5 This is a graph of the tensile stress luminescence test of Example 5. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0024] Example 1: Preparation of stress phosphor SrLa 0.995 GaO4:0.005Tb 3+

[0025] (1) According to the stoichiometric ratio, 0.8197 g of SrCO3 (purity 99.95%), 0.8997 g of La2O3 (purity 99.99%), 0.5202 g of Ga2O3 (purity 99.99%), 0.0051 g of Tb4O7 (purity 99.99%), and 0.0336 g of H3BO3 (purity 99.99%) were weighed and added to an agate mortar to obtain an initial mixed raw material;

[0026] (2) Add alcohol to the obtained mixed powder and grind it evenly in a mortar for 30 minutes, then pour it into an alumina crucible;

[0027] (3) The alumina crucible was placed in a muffle furnace and heated to 1300°C at 5°C / min for sintering, kept at this temperature for 4 h, then cooled to 1000°C at 5°C / min, and then naturally cooled;

[0028] (4) The sintered sample was poured into a mortar and ground again to obtain phosphor SrLa 0.995 GaO4:0.005Tb 3+ .

[0029] Example 2: Preparation of stress phosphor SrLa 0.99 GaO4:0.01Tb 3+

[0030] (1) According to the stoichiometric ratio, 0.8195 g of SrCO3 (purity 99.95%), 0.8949 g of La2O3 (purity 99.99%), 0.5201 g of Ga2O3 (purity 99.99%), 0.0103 g of Tb4O7 (purity 99.99%), and 0.0336 g of H3BO3 (purity 99.99%) were weighed and added to an agate mortar to obtain an initial mixed raw material;

[0031] (2) Add alcohol to the obtained mixed powder and grind it evenly in a mortar for 30 minutes, then pour it into an alumina crucible;

[0032] (3) The alumina crucible was placed in a muffle furnace and heated to 1300°C at 5°C / min for sintering, kept at this temperature for 4 h, then cooled to 1000°C at 5°C / min, and then naturally cooled;

[0033] (4) The sintered sample was poured into the mortar again for grinding, and finally the phosphor SrLa 0.99 GaO4:0.01Tb 3+ .

[0034] Example 3: Preparation of stress phosphor SrLa 0.97 GaO4:0.03Tb 3+

[0035] (1) According to the stoichiometric ratio, 0.8186 g of SrCO3 (purity 99.95%), 0.8759 g of La2O3 (purity 99.99%), 0.5195 g of Ga2O3 (purity 99.99%), 0.0311 g of Tb4O7 (purity 99.99%), and 0.0336 g of H3BO3 (purity 99.99%) were weighed and added to an agate mortar to obtain an initial mixed raw material;

[0036] (2) Add alcohol to the obtained mixed powder and grind it evenly in a mortar for 30 minutes, then pour it into an alumina crucible;

[0037] (3) The alumina crucible was placed in a muffle furnace and heated to 1300°C at 5°C / min for sintering, kept at this temperature for 4 h, then cooled to 1000°C at 5°C / min, and then naturally cooled;

[0038] (4) The sintered sample was poured into the mortar again for grinding, and finally the phosphor SrLa 0.97 GaO4:0.03Tb 3+ .

[0039] Example 4: Preparation of stress phosphor SrLa 0.95 GaO4:0.05Tb 3+

[0040] (1) According to the stoichiometric ratio, 0.8177 g of SrCO3 (purity 99.95%), 0.8568 g of La2O3 (purity 99.99%), 0.5189 g of Ga2O3 (purity 99.99%), 0.0517 g of Tb4O7 (purity 99.99%), and 0.0336 g of H3BO3 (purity 99.99%) were weighed and added to an agate mortar to obtain an initial mixed raw material;

[0041] (2) Add alcohol to the obtained mixed powder and grind it evenly in a mortar for 30 minutes, then pour it into an alumina crucible;

[0042] (3) The alumina crucible was placed in a muffle furnace and heated to 1300°C at 5°C / min for sintering, and kept at this temperature for 4 h, then cooled to 1000°C at 5°C / min, and then cooled naturally;

[0043] (4) The sintered sample was poured into the mortar again for grinding, and finally the phosphor SrLa 0.95 GaO4:0.05Tb 3+ .

[0044] Example 5: Preparation of stress phosphor SrLa 0.93 GaO4:0.07Tb 3+

[0045] (1) According to the stoichiometric ratio, 0.8168 g of SrCO3 (purity 99.95%), 0.8379 g of La2O3 (purity 99.99%), 0.5183 g of Ga2O3 (purity 99.99%), 0.0723 g of Tb4O7 (purity 99.99%), and 0.0336 g of H3BO3 (purity 99.99%) were weighed and added to an agate mortar to obtain an initial mixed raw material;

[0046] (2) Add alcohol to the obtained mixed powder and grind it evenly in a mortar for 30 minutes, then pour it into an alumina crucible;

[0047] (3) The alumina crucible was placed in a muffle furnace and heated to 1300°C at 5°C / min for sintering, and kept at this temperature for 4 h, then cooled to 1000°C at 5°C / min, and then cooled naturally;

[0048] (4) The sintered sample was poured into the mortar again for grinding, and finally the phosphor SrLa 0.93 GaO4:0.07Tb 3+ .

[0049] Example 6: Preparation of stress phosphor SrLa 0.91 GaO4:0.09Tb 3+

[0050] (1) According to the stoichiometric ratio, 0.8159 g of SrCO3 (purity 99.95%), 0.8189 g of La2O3 (purity 99.99%), 0.5177 g of Ga2O3 (purity 99.99%), 0.0929 g of Tb4O7 (purity 99.99%), and 0.0336 g of H3BO3 (purity 99.99%) were weighed and added to an agate mortar to obtain an initial mixed raw material;

[0051] (2) Add alcohol to the obtained mixed powder and grind it evenly in a mortar for 30 minutes, then pour it into an alumina crucible;

[0052] (3) The alumina crucible was placed in a muffle furnace and heated to 1300°C at 5°C / min for sintering, and kept at this temperature for 4 h, then cooled to 1000°C at 5°C / min, and then cooled naturally;

[0053] (4) The sintered sample was poured into the mortar again for grinding, and finally the phosphor SrLa 0.91 GaO4:0.09Tb 3+ .

[0054] In order to characterize stress luminescence, a stress luminescent composite film was obtained by compounding through a mold. The compounding steps are as follows:

[0055] Before characterizing the stress luminescence performance, the stress luminescent material powders prepared in each of the above examples were respectively compounded with PDMS in a dumbbell-shaped polytetrafluoroethylene mold to obtain a stress luminescent composite film. The specific compounding steps are as follows:

[0056] (1) Prepare a PDMS mixture by pouring 2 g of PDMS and 0.2 g of curing agent into a culture dish at a mass ratio of 10:1;

[0057] (2) Weigh 1 g of the stress luminescent material powder from the above examples and add it to a culture dish for mixing;

[0058] (3) Let it stand at room temperature for 5 minutes. After the bubbles are eliminated, pour the mixture into each mold;

[0059] (4) The mold after standing is placed in an oven and kept warm at 60°C for 3 hours, and then demolded to obtain the stress luminescent composite material.

[0060] The relevant scanning electron microscope photos, XRD patterns, photoluminescence spectra, and stress luminescence spectra of the samples prepared in the above examples are as follows: Figure 1-5 shown.

[0061] Figure 1 This is a scanning electron microscope photograph of the sample obtained in Example 5. The size of the sample is less than 10 μm, and the sample surface is smooth and free of impurities.

[0062] Figure 2 The XRD patterns of the samples obtained in Examples 1 to 6 were compared with the standard PDF cards. The results showed that no impurity peaks were generated, indicating that the material was a pure phase of SrLaGaO4, belonging to the tetragonal system with a space group of I4 / mmm.

[0063] Figure 3 The photoluminescence spectrum of the sample prepared in Example 5 is as follows: the excitation wavelength is 274 nm, the emission wavelength is 546 nm, and by analyzing the coordination environment and ionic radius, Tb 3+ La enters the crystal 3+ Location, Tb 3+ As a luminous center.

[0064] Figure 4 This is the stress luminescence spectrum of the sample prepared in Example 5. After being composited with PDMS, it was directly stretched without pre-excitation to obtain the spectrum. The strongest peak is at 546nm, which is basically consistent with the photoluminescence center.

[0065] Figure 5 This is the luminescence phenomenon of the film prepared in Example 5 under stretching, indicating that the stress luminescence material based on terbium-doped gallate compounds can achieve stress luminescence performance under terbium ion doping, and the prepared material can achieve stress luminescence under stress stimulation without ultraviolet light irradiation.

[0066] The above is only an embodiment of the present invention, and common knowledge such as the specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A rare earth ion-doped gallate stress phosphor, characterized in that: The chemical formula of the stress phosphor is: SrLa 1-x GaO4:xTb 3+ , x represents the mole fraction, 0.005≤x≤0.

9.

2. The rare earth ion-doped gallate stress phosphor according to claim 1, characterized in that: The following steps are involved: S1. Accurately weigh the raw materials according to the stoichiometric ratio and place them in an agate mortar to obtain an initial mixed raw material; S2, using anhydrous ethanol as a grinding medium, grinding the mixed raw materials in an agate mortar, and finally transferring the ground product into an alumina crucible; S3. placing the alumina crucible containing the mixture into a muffle furnace, setting a temperature rising program, and sintering in an air atmosphere using a high-temperature solid-phase method; S4. The sample sintered in S3 is cooled to room temperature and taken out, and ground into powder again in an agate mortar to obtain stress luminescent phosphor.

3. The method for preparing a rare earth ion-doped gallate stress phosphor according to claim 2, characterized in that: In S1, the raw materials weighed are SrCO3, La2O3, Ga2O3, and Tb4O7, and H3BO3 is added as a flux. The purity of SrCO3 is 99.95%, and the purity of the remaining raw materials is 99.99%.

4. The method for preparing a rare earth ion-doped gallate stress phosphor according to claim 2, wherein: In S3, the alumina crucible containing the mixture was heated to 1300°C at 5°C / min in a muffle furnace for sintering, kept warm for 4 hours, and then cooled to 1000°C at 5°C / min; then naturally cooled to room temperature, poured into an agate mortar and ground to obtain stress phosphor.

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