Preparation method of rare earth luminescent material

Abstract

The invention relates to a preparation method of a rare earth luminescent material, which comprises the following steps: respectively weighing SrCO3, Al2O3, Q and Eu compounds according to a molar ratio of (1-x-y): 1: x: y as reaction raw materials, Q being any one or more compounds of Sc, Lu, Y and Gd, Eu being one or more selected from Eu2O3, EuCl3, EuF3, Eu (CO3) 3 and Eu (NO3) 3, and y being one or more selected from one or more selected from EuCl3, EuF3, Eu (CO3) 3 and Eu (NO3) 3; wherein X is the mole ratio of any one or more atoms of Sc, Lu, Y and Gd, y is the mole ratio of Eu atoms, the reaction raw materials are ground into dry powder, the ground dry powder is pressed, fired for 4-20 hours in a reducing atmosphere, then rapidly cooled to 500 DEG C and cooled along with a furnace to obtain cooled powder, the obtained cooled powder is ground, and the powder is obtained. The mechanoluminescence of the mechanoluminescence material has an afterglow characteristic.

Description

Technical Field

[0001] The invention relates to the preparation of a luminescent material, in particular to a method for preparing a rare earth luminescent material. Background Art

[0002] In the field of materials science, mechanoluminescent materials have attracted much attention due to their unique properties. These materials can emit visible light when subjected to mechanical force. This property has broad application prospects in the fields of force sensing, safety signs, and optoelectronic devices. Traditional mechanoluminescent materials often have problems such as low luminous efficiency, poor stability or high cost, which limits their large-scale application.

[0003] In recent years, rare earth element doped aluminate materials have gradually become a hot topic in the study of mechanoluminescent materials due to their excellent luminescence properties and good chemical stability. Among them, strontium aluminate doped with europium (SrAl2O4:Eu) as a luminescent material has excellent long afterglow performance. In addition, this material also has certain mechanoluminescence properties and has received widespread attention in recent years. How to enhance the mechanoluminescence properties of SrAl2O4:Eu and broaden its application in the real field is still a difficult problem. The introduction of other inert rare earth elements such as scandium (Sc), lutetium (Lu), yttrium (Y), gadolinium (Gd) as co-dopants can regulate the crystal structure, band structure and luminescence properties of the material, thereby optimizing the mechanoluminescence properties. Moreover, the doping of inert rare earth ions can produce more defect state energy levels, which can enhance the intensity of mechanoluminescence and make the mechanoluminescence have afterglow characteristics.

[0004] Existing rare earth-doped strontium aluminate electroluminescent materials still face certain challenges in the preparation process, such as how to achieve uniform distribution of rare earth elements in the matrix material while ensuring the purity of the material; how to effectively control the crystal structure and phase composition of the material during high-temperature sintering to avoid the formation of unfavorable phases; and how to optimize process parameters such as sintering temperature and time to improve the luminescence efficiency and stability of the material. Summary of the invention

[0005] The invention provides a method for preparing a rare earth luminescent material.

[0006] The method for preparing a rare earth luminescent material is characterized by comprising: SrCO3, Al2O3, and Q and Eu compounds are weighed as reaction raw materials according to the molar ratio (1-xy): 1:x:y, wherein Q is any one or more compounds of Sc, Lu, Y, Gd, and Eu is one or more selected from Eu2O3, EuCl3, EuF3, Eu(CO3)3, and Eu(NO3)3, wherein X is the molar ratio of any one or more atoms of Sc, Lu, Y, and Gd, and y is the molar ratio of Eu atoms; Grind the above reaction materials into dry powder; The ground dry powder is compacted and burned in a reducing gas for 4 to 20 hours, then rapidly cooled to 500° C. and then cooled in a furnace to obtain a cooled powder; The cooled powder is ground to obtain a mesoluminescent material, which emits mesoluminescence.

[0007] Preferably, in the method for preparing the rare earth luminescent material, 0≤y≤0.15, 0≤x≤0.3.

[0008] Preferably, the method for preparing the rare earth luminescent material, grinding the above reaction raw materials into dry powder comprises: Anhydrous ethanol or deionized water is added to the above reaction raw materials, and then ground into dry powder.

[0009] Preferably, the method for preparing the rare earth luminescent material, adding anhydrous ethanol to the above reaction raw materials, and then grinding to dry powder comprises: Add anhydrous ethanol or deionized water to the above reaction materials at least twice and then grind to dry powder.

[0010] Preferably, in the method for preparing any of the rare earth luminescent materials, the ground dry powder is placed in an oven for drying.

[0011] Preferably, in the method for preparing the rare earth luminescent material, the ground dry powder is placed in an oven at 80° C. for drying.

[0012] Preferably, in the method for preparing the rare earth luminescent material, the reducing gas is 5% H2 / 95% Ar.

[0013] Preferably, the calcining in a reducing gas for 4 to 20 hours specifically comprises: heating to 1300 to 1700° C. at 1° C. / min to 30° C. / min in a 5% H2 / 95% Ar reducing atmosphere, and calcining for 4 to 20 hours.

[0014] Preferably, the rapid cooling to 500°C and then furnace cooling to obtain the cooled powder specifically comprises: controlling the cooling rate to be 1°C / min to 30°C / min until 500°C and then furnace cooling.

[0015] Preferably, the step of grinding the cooled powder to obtain the mechanoluminescent material comprises grinding the cooled powder for 10 to 30 minutes to obtain the mechanoluminescent material.

[0016] A method for preparing a rare earth luminescent material provided by an embodiment of the present invention can cause local lattice distortion of the matrix material and adjust defect energy levels through doping, so that the intensity of mechanoluminescence can be enhanced, and bright visible light can be emitted under the action of a smaller force. At the same time, due to the increase in defect energy levels, the material can have mechanoluminescence afterglow and its afterglow time under photoluminescence can be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 is the mesoluminescence intensity of exemplary strontium aluminate phosphors doped with different rare earth ions provided by an embodiment of the present invention; Figure 2 It is a flow chart of an exemplary method for preparing rare earth luminescent materials provided in an embodiment of the present invention. Specific embodiments

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0020] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0021] Example 1: Sr 0.9 Al2O4:Sc 0.08 ,Eu 0.02 Preparation of mechanoluminescent materials This example describes Sr in detail. 0.9 Al2O4:Sc 0.08 ,Eu 0.02 The preparation method of the mechanoluminescent material comprises the following specific steps: Step 1: Preparation and Mixing Accurately weigh 1.7272g SrCO3, 1.3255g Al2O3, 0.0458g Eu2O3 and 0.0716g Sc2O3 as starting materials, add the above raw materials into an agate mortar, and add an appropriate amount of anhydrous ethanol or deionized water as a grinding medium. Subsequently, the raw materials are fully ground until they are evenly mixed to form a fine slurry. The ground slurry is placed in an oven at 80°C for drying to remove residual moisture and solvent to obtain a dry mixed powder.

[0022] Step 2: Calcination The evenly ground mixed powder is placed in an alumina crucible and gently pressed to ensure close contact between the powders. Subsequently, the crucible is placed in a tubular furnace and calcined in a reducing atmosphere of 5% H2 / 95% Ar. During the calcination process, the temperature is slowly increased to a temperature point between 1300°C and 1700°C at a heating rate of 1°C / min to 10°C / min, and the temperature is maintained for 4 to 12 hours to ensure that the raw materials are fully reacted and the target product is formed. After the calcination is completed, the temperature is slowly reduced to 500°C at a cooling rate of 1°C / min to 5°C / min, and then naturally cooled to room temperature with the furnace.

[0023] Step 3: Post-processing and finished product preparation The calcined and cooled powder is placed in an agate mortar again for fine grinding for 10 to 30 minutes to refine the powder particles and improve their dispersibility. The final powder is the mechanoluminescent material Sr with long afterglow characteristics. 0.9 Al2O4:Sc 0.08 ,Eu 0.02 .

[0024] Embodiment 2: Sr 0.9 Al2O4:Lu 0.08 ,Eu 0.02 Preparation of mechanoluminescent materials The preparation method of this embodiment is similar to that of the first embodiment, except that the raw material composition is different. The specific steps are as follows: Step 1: Preparation and Mixing Accurately weigh 1.7272 g SrCO3, 1.3255 g Al2O3, 0.0458 g Eu2O3 and 0.2069 g Lu2O3 as starting materials, add the above raw materials into an agate mortar, and add an appropriate amount of anhydrous ethanol or deionized water as a grinding medium. Subsequently, the raw materials are fully ground until they are evenly mixed to form a fine slurry. The ground slurry is placed in an oven at 80°C for drying to remove residual moisture and solvent to obtain a dry mixed powder.

[0025] Step 2: Calcination The uniformly ground mixed powder is placed in an alumina crucible and lightly pressed to ensure close contact between the powders. Subsequently, the crucible is placed in a tube furnace and calcined in a reducing atmosphere of 5% H2 / 95% Ar. During the calcination process, the temperature is slowly increased to a temperature point between 1300°C and 1700°C at a heating rate of 1°C / min to 10°C / min, and the temperature is maintained for 4 to 12 hours to ensure that the raw materials are fully reacted and the target product is formed. After the calcination is completed, the mixture is heated at 1 °C / min to 1 °C / min. o C / min to 5 o The temperature was slowly lowered to 500 C / min. o C, and then naturally cooled to room temperature in the furnace.

[0026] Step 3: Post-processing and finished product preparation The calcined and cooled powder is placed in an agate mortar again for fine grinding for 10 to 30 minutes to refine the powder particles and improve their dispersibility. The final powder is the mechanoluminescent material Sr with long afterglow characteristics. 0.9 Al2O4:Lu 0.08 ,Eu 0.02 .

[0027] Embodiment 3: Sr 0.9Al2O4:Y 0.08 ,Eu 0.02 Preparation of mechanoluminescent materials The preparation method of this embodiment is similar to that of the first embodiment, except that the dopant in the raw material is replaced with Y2O3. The specific steps are as follows: Step 1: Preparation and Mixing Accurately weigh 1.7272g SrCO3, 1.3255g Al2O3, 0.0458g Eu2O3 and 0.1174g Y2O3 as starting materials, add the above raw materials into an agate mortar, and add an appropriate amount of anhydrous ethanol or deionized water as a grinding medium. Subsequently, the raw materials are fully ground until they are evenly mixed to form a fine slurry. The ground slurry is placed in an oven at 80°C for drying to remove residual moisture and solvent to obtain a dry mixed powder.

[0028] Step 2: Calcination The evenly ground mixed powder is placed in an alumina crucible and gently pressed to ensure close contact between the powders. Subsequently, the crucible is placed in a tubular furnace and calcined in a reducing atmosphere of 5% H2 / 95% Ar. During the calcination process, the temperature is slowly increased to a temperature point between 1300°C and 1700°C at a heating rate of 1°C / min to 10°C / min, and the temperature is maintained for 4 to 12 hours to ensure that the raw materials are fully reacted and the target product is formed. After the calcination is completed, the temperature is slowly reduced to 500°C at a cooling rate of 1°C / min to 5°C / min, and then naturally cooled to room temperature with the furnace.

[0029] Step 3: Post-processing and finished product preparation.

[0030] The calcined and cooled powder is placed in an agate mortar again for fine grinding for 10 to 30 minutes to refine the powder particles and improve their dispersibility. The final powder is the mechanoluminescent material Sr with long afterglow characteristics. 0.9 Al2O4:Y 0.08 ,Eu 0.02 .

[0031] Embodiment 4: Sr 0.9 Al2O4:Gd 0.08 ,Eu 0.02 Preparation of mechanoluminescent materials.

[0032] The preparation method of this embodiment is similar to that of the first embodiment, except that the dopant in the raw material is replaced with Gd2O3. The specific steps are as follows: Step 1: Preparation and Mixing Accurately weigh 1.7272g SrCO3, 1.3255g Al2O3, 0.0458g Eu2O3 and 0.188g Gd2O3 as starting materials, add the above raw materials into an agate mortar, and add an appropriate amount of anhydrous ethanol or deionized water as a grinding medium. Subsequently, the raw materials are fully ground until they are evenly mixed to form a fine slurry. The ground slurry is placed in an oven at 80°C for drying to remove residual moisture and solvent to obtain a dry mixed powder.

[0033] Step 2: Calcination treatment.

[0034] The evenly ground mixed powder is placed in an alumina crucible and gently pressed to ensure close contact between the powders. Subsequently, the crucible is placed in a tubular furnace and calcined in a reducing atmosphere of 5% H2 / 95% Ar. During the calcination process, the temperature is slowly increased to a temperature point between 1300°C and 1700°C at a heating rate of 1°C / min to 10°C / min, and the temperature is maintained for 4 to 12 hours to ensure that the raw materials are fully reacted and the target product is formed. After the calcination is completed, the temperature is slowly reduced to 500°C at a cooling rate of 1°C / min to 5°C / min, and then naturally cooled to room temperature with the furnace.

[0035] Step 3: Post-processing and finished product preparation.

[0036] The calcined and cooled powder is placed in an agate mortar again for fine grinding for 10 to 30 minutes to refine the powder particles and improve their dispersibility. The final powder is the mechanoluminescent material Sr with long afterglow characteristics. 0.9 Al2O4:Y 0.08 ,Eu 0.02 .

[0037] Embodiment 5: Sr 0.92 Al2O4:Eu 0.02 Preparation of mechanoluminescent materials The preparation method of this embodiment is similar to that of the first embodiment, but does not contain dopants such as Sc³⁺, Lu³⁺, Y³⁺ or Gd³⁺. The specific steps are as follows: Step 1: Preparation and mixing.

[0038] Accurately weigh 1.881g SrCO3, 1.3255g Al2O3 and 0.0458g Eu2O3 as starting materials, add the above raw materials into an agate mortar, and add an appropriate amount of anhydrous ethanol or deionized water as a grinding medium. Subsequently, the raw materials are fully ground until they are evenly mixed to form a fine slurry. The ground slurry is placed in an oven at 80°C for drying to remove residual moisture and solvent to obtain a dry mixed powder.

[0039] Step 2: Calcination treatment.

[0040] The evenly ground mixed powder is placed in an alumina crucible and gently pressed to ensure close contact between the powders. Subsequently, the crucible is placed in a tubular furnace and calcined in a reducing atmosphere of 5% H2 / 95% Ar. During the calcination process, the temperature is slowly increased to a temperature point between 1300°C and 1700°C at a heating rate of 1°C / min to 10°C / min, and the temperature is maintained for 4 to 12 hours to ensure that the raw materials are fully reacted and the target product is formed. After the calcination is completed, the temperature is slowly reduced to 500°C at a cooling rate of 1°C / min to 5°C / min, and then naturally cooled to room temperature with the furnace.

[0041] Step 3: Post-processing and finished product preparation.

[0042] The calcined and cooled powder is placed in an agate mortar again for fine grinding for 10 to 30 minutes to refine the powder particles and improve their dispersibility. The final powder is the mechanoluminescent material Sr with long afterglow characteristics. 0.92 Al2O4:,Eu 0.02 .

[0043] pass Figure 1-2 It can be seen that the preparation process of mixing different raw materials is basically the same, but the materials prepared by different raw materials have different effects. Lanthanide ion doping can enhance the luminescence intensity of strontium aluminate luminescent materials by 3 to 8 times, among which Sc 3+ Ion-doped samples SrAl2O4:Eu 2+ The intensity of mechanoluminescent materials is enhanced without significantly enhancing the afterglow. The same doping can make SrAl2O4:Eu 2+ ,Dy 3+ The intensity, afterglow intensity and afterglow time of mesoluminescence are all enhanced, thus expanding its application areas.

[0044] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are descriptive and exemplary, rather than restrictive terms. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above-mentioned embodiments are not limited to any of the foregoing details, but should be broadly interpreted within the spirit and scope defined by the appended claims. Therefore, all changes and modifications that fall within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for preparing a rare earth luminescent material, characterized in that: include: SrCO3, Al2O3, and Q and Eu compounds are weighed as reaction raw materials according to the molar ratio (1-xy): 1:x:y, wherein Q is any one or more compounds of Sc, Lu, Y, Gd, and Eu is one or more selected from Eu2O3, EuCl3, EuF3, Eu(CO3)3, and Eu(NO3)3, wherein X is the molar ratio of any one or more atoms of Sc, Lu, Y, and Gd, and y is the molar ratio of Eu atoms; Grind the above reaction materials into dry powder; The ground dry powder is compacted and burned in a reducing gas for 4 to 20 hours, and then rapidly cooled to 500° C. and then cooled in a furnace to obtain a cooled powder; The cooled powder is ground to obtain a mesoluminescent material, which emits mesoluminescence.

2. The method for preparing the rare earth luminescent material according to claim 1, characterized in that: Among them, 0≤y≤0.15, 0≤x≤0.

3.

3. The method for preparing the rare earth luminescent material according to claim 1, characterized in that: Grinding the above reaction raw materials into dry powder comprises: Anhydrous ethanol or deionized water is added to the above reaction raw materials, and then ground into dry powder.

4. The method for preparing the rare earth luminescent material according to claim 2, characterized in that: Adding anhydrous ethanol to the above reaction raw materials, and then grinding to dry powder includes: Add anhydrous ethanol or deionized water to the above reaction materials at least twice and then grind to dry powder.

5. The method for preparing any rare earth luminescent material according to claim 3 or 4, characterized in that: The ground dry powder is placed in an oven for drying.

6. The method for preparing the rare earth luminescent material according to claim 5, characterized in that: The ground dry powder was placed in an oven at 80°C for drying.

7. The method for preparing the rare earth luminescent material according to claim 1, characterized in that: The reducing gas is 5% H2 / 95% Ar.

8. The method for preparing the rare earth luminescent material according to claim 7, characterized in that: The calcining in the reducing gas for 4 to 20 hours specifically includes: heating to 1300 to 1700° C. at 1° C. / min to 30° C. / min in a 5% H2 / 95% Ar reducing atmosphere, and calcining for 4 to 20 hours.

9. The method for preparing the rare earth luminescent material according to claim 1, characterized in that: The method of rapidly cooling the temperature to 500°C and then cooling the powder in the furnace to obtain the cooled powder specifically includes: controlling the cooling rate to be 1°C / min to 30°C / min until the temperature reaches 500°C and then cooling the powder in the furnace.

10. The method for preparing a rare earth luminescent material according to claim 1, characterized in that: The step of grinding the cooled powder to obtain the mechanoluminescent material specifically comprises grinding the cooled powder for 10 to 30 minutes to obtain the mechanoluminescent material, wherein the mechanoluminescence has afterglow characteristics.

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