Fluorescent heat-enhanced ceramic glass and its preparation method and application

Abstract

The present invention relates to the field of solid fluorescent materials. A fluorescent thermally enhanced ceramic glass is a composite material in which rare earth ion-doped fluorescent nanocrystals are distributed in a glass matrix; the rare earth ion-doped fluorescent nanocrystals are composed of xLn: Yb2M3O 12 , where Ln is Nd 3+ ,Er 3+ or Tm 3+ M is one of W or Mo; the Ln doping concentration is x = 2 ~ 10mol%. The fluorescent thermally enhanced ceramic glass of the present invention has an up-conversion fluorescent thermal enhancement effect under 980nm laser excitation and can be used as a fluorescence intensity ratio temperature sensing material.

Description

Technical Field

[0001] The present invention relates to the field of solid fluorescent materials, and in particular to a fluorescent ceramic glass with up-conversion fluorescence thermal enhancement effect that can be used for temperature sensing and a preparation method thereof. Background Art

[0002] Temperature has a significant impact on many physical, chemical, and biological processes, making it essential for accurate measurement and monitoring. Traditional contact temperature sensors, such as mercury meters and thermocouples, are limited by their measurement methods and therefore struggle to meet the demands of testing in complex environments, such as living tissue, rapidly moving objects, and highly corrosive environments. In recent years, non-contact temperature sensing technology based on fluorescent materials has become a hot topic of research, promising to overcome the limitations of traditional thermometers. This technology primarily detects temperature by measuring the relationship between the optical parameters of fluorescent materials (such as fluorescence intensity, fluorescence intensity ratio, or fluorescence lifetime) and temperature. Fluorescence intensity ratio technology, in particular, uses the intensity ratio of two fluorescence peaks with different temperature responses to reflect temperature changes. This technology is unaffected by non-temperature factors such as electromagnetic fields, fluorescence loss, and fluctuations in the excitation light source, demonstrating significant advantages and meeting the temperature measurement needs of applications in fields such as life sciences, aerospace, and microelectronics.

[0003] At present, fluorescence intensity ratio temperature measurement technology is mainly divided into single rare earth ion thermal coupling energy level temperature measurement (such as Er 3 + : 2 H 11 / 2 , 4 S 3 / 2 , Ho 3+ : 5 F 2,3 / 3 K8, 5 G6 / 5 G1, Tm 3+ : 3 F 2,3, 3 H4, etc.) and construct dual fluorescence center temperature measurement (such as Er 3+ / Nd 3+ , Tb 3+ / Pr 3+ 、Eu 3+ / Cr 3+ For example, Luo et al. reported a ferroelectric ceramic that can be used for fluorescence temperature sensing. Under 980nm excitation, Er 3+ Ion thermal coupling energy level pair 2 H 11 / 2 and 4 S 3 / 2The fluorescence intensity ratio is used as the temperature measurement parameter, which can realize temperature sensing in the temperature range of 133~573K. The relative sensitivity of temperature measurement at room temperature is 0.8%K. -1 (DOI: 10.1016 / j.jeurceramsoc.2017.09.035). However, due to the gradual enhancement of lattice thermal vibrations at high temperatures, most fluorescent materials face the problem of thermal quenching of fluorescence. This thermal quenching effect not only reduces the fluorescence efficiency of fluorescent materials at high temperatures but also changes the light color parameters, which undoubtedly has a negative impact on the accuracy and resolution of temperature measurements at high temperatures. Therefore, the development of temperature probe materials that combine thermal fluorescence enhancement with high temperature measurement sensitivity is of great significance.

[0004] Recently, Er 3+ : Yb2W3O 12 、Er 3+ / Yb 3+ : Sc2Mo3O 12 Constant negative thermal expansion type A2M3O 12 The thermal enhancement of fluorescence of materials (A=Yb, Y, Sc and other trivalent metals; M=Mo or W) has attracted research interest. 12 The shrinkage of the matrix lattice effectively improves the energy transfer efficiency between the sensitizing ions and the activating ions, thereby achieving thermal enhancement of the upconversion fluorescence of the activated ions. At the same time, this type of material has also shown good application prospects in the field of fluorescence temperature sensing. For example, Bai Gongxun et al. reported that when the temperature was increased from 313K to 573K, Er 3+ : Yb2Mo3O 12 The upconversion luminescence intensity under 980nm excitation increased by 21 times; and through 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 The fluorescence intensity ratio realizes temperature sensing with a maximum relative sensitivity of 1.23%K -1 (DOI: 10.1063 / 5.0046818). Although this type of A2M3O 12 The material has attracted considerable attention, but at room temperature, water molecules easily invade the voids of its framework lattice. This not only causes the material to lose its negative thermal expansion properties but also reduces the luminescence performance of the doped rare earth ions, severely restricting its application in fluorescent materials and devices. Summary of the Invention

[0005] The purpose of the present invention is to provide a ceramic glass that can be used for fluorescence temperature sensing and has a fluorescence thermal enhancement effect. 12 (M = W, Mo) nanocrystals are composited with borosilicate glass, using the glass matrix to effectively isolate Yb2M3O 12 Direct contact with the air environment solves the problem of its strong water absorption.

[0006] In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions: a fluorescent thermally enhanced ceramic glass, which is a composite material of rare earth ion-doped fluorescent nanocrystals distributed in a glass matrix; the composition of the rare earth ion-doped fluorescent nanocrystals is xLn: Yb2M3O 12 , where Ln is Nd 3+ , Er 3+ or Tm 3+ M is one of W or Mo; the Ln doping concentration is x = 2~10mol%.

[0007] Preferably, the glass matrix is ​​made of the following raw materials: SiO2: 66~70mol%, Al2O3: 6~8mol%, CaO: 0.5~1.2mol%, Na2CO3: 1.5~2.5mol%, K2CO3: 0.5~0.8mol%, H3BO3: 11.7~14mol%, BaO: 0.3~0.8mol%, MgO: 2~4mol%, Yb2O3: 2~3mol%, and the total molar amount of the above components is 100 mol%.

[0008] Preferably, the mass fraction of the nanocrystals in the ceramic glass is 3-5%.

[0009] The method for preparing the fluorescent thermally enhanced ceramic glass comprises the following steps:

[0010] (1) Preparation of glass powder: According to the designed molar ratio, each raw material is placed in a ZrO2 ceramic jar, and a certain amount of ZrO2 ceramic balls are added, with a ball-to-material ratio of 10:1; the materials are ball-milled for 1 hour on a planetary ball mill at a speed of 100 rpm; then, the obtained mixed powder is placed in a corundum crucible, heated to 1500~1650℃ and kept warm for 0.5~1.2 hours; then, the glass melt is quickly poured into water for rapid cooling, taken out and dried, and then the glass body is crushed and ground into powders of different particle sizes in a mortar; the obtained powder is sieved through 100 and 300 mesh sieves respectively to obtain borosilicate glass powder for use;

[0011] (2) Ln:Yb2M3O 12 (Ln = Nd 3+ , Er 3+ , Tm3+ Preparation of nanocrystals: Take Ln 3+ and Yb 3+ The rare earth nitrate, ammonium molybdate or ammonium tungstate corresponding to the ions are placed in different beakers, deionized water is added and magnetically stirred until completely dissolved to obtain the corresponding solutions for use; the solutions are mixed according to the stoichiometric ratio of the nanocrystals and magnetically stirred for 1 hour to obtain a mixed solution; a certain amount of organic complexing agent is added to the mixed solution so that the molar ratio of the total amount of metal cations in the solution to the complexing agent is 10:1, and the solutions are mixed and stirred at 60-90°C for 0.5-1 hour; then, the pH value of the mixed solution is adjusted to 5.5-6.5 by dropwise addition of ammonia water. 6.5. After continuous stirring for 1-1.5 hours, a suspension is obtained. The suspension is transferred to an oven and kept at 100-120°C for 3-4 hours to form a dry gel. The dry gel is placed in a corundum crucible, placed in a pit furnace, and calcined at 400-550°C for 2-3 hours to obtain a precursor. After the precursor is evenly ground, it is placed in a high-temperature sintering furnace, heated to 950-1100°C at a rate of 5°C / min, and kept at this temperature for 2-4 hours. After cooling to room temperature in the furnace, it is ground for 15 minutes to obtain fluorescent nanocrystals for use.

[0012] (3) Preparation of ceramic glass: The glass powders passed through a 100-mesh sieve and a 300-mesh sieve obtained in the above step (1) were mixed in a mass ratio of (95-97): (5-3), and stirred in a mortar for 30 minutes; the obtained glass powders were mixed with the nanocrystals obtained in step (2) in a certain mass ratio, and stirred in a mortar for 30 minutes; then, an appropriate amount of powder was loaded into a high-strength steel mold, and a uniaxial tablet press was used to press a green blank with a diameter of about 13 mm at a pressure of 300-400 MPa for 2-3 minutes, and the green blank was placed in a box furnace, and the temperature was increased to 700-750°C at a heating rate of 5°C / min. After sintering in an air atmosphere for 10-20 minutes, the green blank was cooled to room temperature in the furnace; finally, the obtained block was machined, and a fluorescent ceramic glass sheet with a thickness of about 0.8 mm was obtained by grinding and polishing.

[0013] In the step (2), preferably, the organic complexing agent is any one of glycine and citric acid.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) First, borosilicate glass with low thermal expansion coefficient and Ln:Yb2M3O 12Nanocrystal composite. This not only avoids the large internal stress generated during the heating process due to the large difference in thermal expansion coefficients between the two, but also reduces the potential impact of the thermal expansion characteristics of the glass itself on the thermal expansion properties of the nanocrystal. In addition, by introducing an appropriate amount of Yb2O3 as a network modifier into the glass matrix, the glass network stability and chemical stability can be enhanced, and it helps to inhibit the Yb in the nanocrystal. 3+ Finally, by mixing glass powders of different particle sizes, the small-sized glass powders fill the pores formed by the accumulation of large-sized glass powders, which helps to improve the uniformity of the melted glass, reduce internal bubbles and porosity, and increase the light transmittance of the glass.

[0016] (2) Through the protection of borosilicate glass matrix, the Ln:Yb2M3O 12 Due to the problems of fluorescence quenching and disappearance of negative thermal expansion characteristics caused by the easy adsorption of water molecules, Ln: Yb2M3O 12 Nanocrystals can maintain the upconversion fluorescence thermal enhancement characteristics. That is, under 980nm laser excitation, as the temperature rises from room temperature to 573K, Ln 3+ Ions (Ln=Nd 3+ 、Er 3+ 、Tm 3+ The upconversion fluorescence intensity of Yb2M3O 12 The thermal contraction of the lattice increases the 3+ →Ln 3+ Since the process does not change the phase and surface structure, Ln 3+ The upconversion fluorescence intensity has good cyclicity with temperature.

[0017] (3) The present invention is to convert the easily water-absorbing Yb2M3O 12 The negative thermal expansion material is compounded with the glass matrix to solve the problem of strong water absorption. It has strong processability and is easy to promote on a large scale. This method is also applicable to solving other A2M3O 12 The water absorption problem of negative thermal expansion materials is solved to promote the practical application of such materials.

[0018] (4) This material realizes temperature sensing function by utilizing the relationship between the fluorescence intensity ratio and temperature through the thermal coupling energy level pair characteristics of rare earth ions. Since the upconversion fluorescence intensity gradually increases with the increase of temperature in the temperature range from room temperature to 573K (λ ex = 980 nm), and the maximum relative sensitivity of temperature measurement can reach 2.76%K -1 ,This feature helps to achieve high-precision temperature measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a photo of the fluorescent ceramic glass prepared in Example 1 under sunlight;

[0020] Figure 2 X-ray diffraction patterns of the glass powder and fluorescent ceramic glass prepared in Example 1;

[0021] Figure 3 This is a scanning electron microscope photograph of the fluorescent ceramic glass prepared in Example 1;

[0022] Figure 4 This is the thermogravimetric curve of the fluorescent ceramic glass prepared in Example 1;

[0023] Figure 5a The up-conversion luminescence temperature-dependent spectrum of the fluorescent ceramic glass prepared in Example 1 (980 nm laser excitation);

[0024] Figure 5b The Nd in the fluorescent ceramic glass prepared in Example 1 3+ Ionic 4 F 7 / 2 → 4 I 9 / 2 、 4 F 5 / 2 → 4 I 9 / 2 and 4 F 3 / 2 → 4 I 9 / 2 Graph showing the variation of luminous intensity with temperature;

[0025] Figure 6 is the fluorescence intensity ratio of the fluorescent ceramic glass prepared in Example 1 (I 752 / I 868 ) and temperature (980nm laser excitation); the inset is the relative sensitivity change of the sample at different temperatures;

[0026] Figure 7 9%Nd:Yb2W3O prepared in Comparative Example 1 12 Transmission electron micrograph of nanocrystals;

[0027] Figure 8 9%Nd:Yb2W3O prepared in Comparative Example 1 12 Thermogravimetric curves of nanocrystals;

[0028] Figure 9 9%Nd:Yb2W3O prepared in Comparative Example 1 12 The fluorescence intensity ratio of nanocrystals (I 752 / I 868 ) versus temperature (980 nm laser excitation); the inset shows the change in relative sensitivity with temperature. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to provide a complete and comprehensive description of the technical solutions in the embodiments of the present invention, and further explain the invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Given the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Example 1

[0031] 2g of glass powder raw material was weighed according to the ratio of 70SiO2:6Al2O3:0.5CaO:1.9Na2CO3:0.8K2CO3:13.6H3BO3:0.8BaO:3.4MgO:3Yb2O3 (molar percentage), placed in a ZrO2 ball mill jar containing 20gZrO2 balls, and ball-milled on a planetary ball mill at a speed of 100rpm for 1h; the obtained mixed powder was placed in a corundum crucible, heated to 1500℃ and kept warm for 1.2h; the glass solution was quickly poured into water for rapid cooling, and after drying, the bulk glass was crushed and ground into powder in a mortar; the obtained powder was sieved through 100 and 300 mesh sieves respectively for later use;

[0032] Prepare Nd(NO3)3, Yb(NO3)3 and ammonium tungstate solutions with a concentration of 0.05 mol / L respectively. 12 Chemical formula, 3.6, 36.4 and 5 mL of Nd(NO3)3, Yb(NO3)3 and ammonium tungstate solution respectively were measured and placed in a beaker, and a mixed solution was obtained after magnetic stirring for 1 hour; 1.9212 g of citric acid was added to the mixed solution, and the mixture was stirred at 90°C for 0.5 hour; thereafter, the pH value of the mixed solution was adjusted to 5.5 by dropping ammonia water, and a suspension was obtained after stirring for 1 hour; the obtained suspension was transferred to a 100°C oven and kept warm for 4 hours to form a dry gel; the dry gel was placed in a crucible, placed in a pit furnace, and calcined at 400°C for 3 hours to obtain a precursor powder; after the precursor was evenly ground, it was placed in a high-temperature sintering furnace, heated to 950°C at a rate of 5°C / min, and kept warm for 4 hours; the obtained powder was cooled to room temperature with the furnace and ground for 15 minutes to obtain fluorescent nanocrystals for use;

[0033] Weigh 0.4608g of glass powder that passed through a 100-mesh sieve and 0.0192g of glass powder that passed through a 300-mesh sieve, stir and mix for 30 minutes, and then mix the glass powder with 0.02g of 9% Nd:Yb2W3O 12The nanocrystals were mixed and ground in a mortar for 30 minutes. After that, the mixed powder was loaded into a high-strength steel mold and pressed into a green blank with a diameter of about 13 mm using a uniaxial tablet press at a pressure of 300 MPa for 3 minutes. The green blank was placed in a box furnace and heated to 700°C at a heating rate of 5°C / min. After sintering for 20 minutes in an air atmosphere, it was cooled to room temperature in the furnace. Finally, the obtained glass body was mechanically processed and a fluorescent ceramic glass sheet with a thickness of 0.8 mm was obtained by grinding and polishing.

[0034] Figure 1 The actual picture of the prepared fluorescent ceramic glass body shows that it has a high transmittance. Figure 2 As shown, X-ray diffraction data show that 9%Nd:Yb2W3O in a borosilicate glass matrix 12 The nanocrystals remain in a well-crystalline orthorhombic phase with no obvious impurity peaks, indicating that the glass matrix has no effect on the crystal structure of the nanocrystals. Scanning electron microscopy shows that Figure 3 As shown, there is no obvious pore in the glass matrix, 9%Nd:Yb2W3O 12 The nanocrystals are evenly distributed inside the glass matrix. Thermogravimetric analysis of the prepared samples shows that the material has almost no weight loss in the range from room temperature to 873K, showing excellent thermal stability, which indicates that the sample has good resistance to moisture absorption. Figure 4 shown. Figure 5a This is the temperature-dependent spectrum of the upconversion luminescence of the sample under 980nm laser excitation. When the sample temperature rises from room temperature to 573K, Nd 3+ Ionic 4 F 7 / 2 → 4 I 9 / 2 、 4 F 5 / 2 → 4 I 9 / 2 and 4 F 3 / 2 → 4 I 9 / 2 The transitions were enhanced by 96, 22, and 5 times, respectively ( Figure 5b ).because 4 F 7 / 2 and 4 F 3 / 2 For thermally coupled energy level pairs, 4 F 7 / 2 → 4 I 9 / 2 (752nm) and 4 F 3 / 2 → 4 I 9 / 2 Fluorescence temperature sensing is performed based on the relationship between the (868nm) transition intensity ratio and temperature. Figure 6 It can be seen that as the temperature increases, the fluorescence intensity ratio (LIR=I 752 / I 868 ) is continuously enhanced, and its relationship with temperature can be well fitted by the Boltzmann relation LIR=Aexp(-B / T), and the highest relative sensitivity is 2.76%K at 298K. -1 .

[0035] Comparative Example 1

[0036] In order to compare the effect of glass matrix, 9% Nd: Yb2W3O was prepared by sol-gel method. 12 Nanocrystals. The specific preparation method is the same as that in Example 1 9% Nd: Yb2W3O 12 The method is consistent with that of nanocrystals.

[0037] Through transmission electron microscopy, it can be seen that the average grain size of the prepared nanocrystals is about 50nm. Figure 7 As shown. Figure 8 It can be seen that the nanocrystal loses weight in the temperature range from room temperature to 386K, and loses about 3.56% of its weight when it reaches thermal equilibrium, indicating that when there is no glass matrix protection, 9%Nd:Yb2W3O 12 Nanocrystals have strong water absorption at room temperature. Figure 9 The fluorescence intensity ratio of the nanocrystal is shown (LIR=I 752 / I 868 ) and temperature. Figure 9 The inset shows the curve of its relative temperature sensitivity changing with temperature. As can be seen from the figure, although the fluorescence intensity ratio of the nanocrystal also shows a certain exponential relationship with temperature, its maximum relative temperature sensitivity is about 2.07%K. -1 , which is lower than the relative sensitivity of the nanocrystal in ceramic glass. This shows that 9%Nd:Yb2W3O 12 When nanocrystals absorb water at room temperature, their negative thermal expansion characteristics will be inhibited, thereby affecting the temperature dependence of the upconversion fluorescence of the doped rare earth ions and reducing their temperature measurement sensitivity.

[0038] Example 2

[0039] 2g of glass powder raw material was weighed according to the ratio of 66SiO2:8Al2O3:1.2CaO:2.5Na2CO3:0.6K2CO3:14H3BO3:0.7BaO:4MgO:3Yb2O3 (molar percentage), placed in a ZrO2 ball mill containing 20g of ZrO2 balls, and ball-milled on a planetary ball mill at a speed of 100rpm for 1h; the obtained mixed powder was placed in a corundum crucible, heated to 1650℃ and kept warm for 0.5h; the glass melt was quickly poured into water for rapid cooling, and after drying, the bulk glass was crushed and ground into powder in a mortar; the obtained powder was sieved through 100 and 300 mesh sieves respectively for later use;

[0040] Based on 9%Nd:Yb2Mo3O 12 Chemical formula: 3.6, 36.4, and 8.6 mL of 0.05 mol / L Nd(NO3)3, Yb(NO3)3, and ammonium molybdate solution, respectively, were measured and placed in a beaker, and a mixed solution was obtained after magnetic stirring for 1 hour; 1.1261 g of glycine was added to the mixed solution, and the mixture was stirred at 90°C for 0.5 hour; thereafter, the pH value of the mixed solution was adjusted to 6.5 by dropwise addition of ammonia water, and a suspension was obtained after stirring for 1.5 hours; the obtained suspension was transferred to a 120°C oven and kept warm for 3 hours to form a dry gel; the dry gel was placed in a pit furnace and calcined at 550°C for 2 hours to obtain a precursor powder; after the precursor was evenly ground, it was placed in a high-temperature sintering furnace, heated to 1100°C at a rate of 5°C / min, kept warm and calcined for 2 hours, cooled to room temperature with the furnace, and then ground for 15 minutes to obtain fluorescent nanocrystals for use;

[0041] Weigh 0.4608g of glass powder that passed through a 100-mesh sieve and 0.0143g of glass powder that passed through a 300-mesh sieve, stir and mix for 30 minutes, and then mix the glass powder with 0.025g of 9% Nd:Yb2Mo3O 12 The nanocrystals were ground and mixed in a mortar for 30 minutes. The powder was then loaded into a high-strength steel mold and pressed into a green blank with a diameter of approximately 13 mm using a uniaxial tablet press at a pressure of 400 MPa for 2 minutes. The green blank was placed in a box furnace and heated to 750°C at a heating rate of 5°C / min. After sintering for 10 minutes in an air atmosphere, it was cooled to room temperature in the furnace. Finally, the obtained glass body was mechanically processed and a fluorescent ceramic glass sheet with a thickness of 0.8 mm was obtained by grinding and polishing.

[0042] The obtained product was tested by up-conversion luminescence temperature spectrum. The results showed that when the temperature was raised from room temperature to 573K under 980nm excitation, Nd 3+ Ionic 4 F 7 / 2 → 4 I 9 / 2 、4 F 5 / 2 → 4 I 9 / 2 and 4 F 3 / 2 → 4 I 9 / 2 The transitions were enhanced by 53.6, 12.5, and 3.6 times, respectively. 4 F 7 / 2 → 4 I 9 / 2 and 4 F 3 / 2 → 4 I 9 / 2 The relationship between the transition intensity ratio and temperature is used for fluorescence temperature sensing, and its highest relative sensitivity is 2.17%K at 298K. -1 .

[0043] Example 3

[0044] 2g of glass powder raw material was weighed according to the ratio of 69SiO2:8Al2O3:1CaO:2.5Na2CO3:0.5K2CO3:11.7H3BO3:0.3BaO:4MgO:3Yb2O3 (molar percentage), placed in a ZrO2 ball mill containing 20gZrO2 balls, and ball-milled on a planetary ball mill at a speed of 100rpm for 1h. The obtained mixed powder was placed in a corundum crucible, heated to 1500℃ and kept warm for 1.2h. The glass melt was quickly poured into water for rapid cooling, and after drying, the bulk glass was crushed and ground into powder in a mortar. The obtained powder was sieved through 100 and 300 mesh sieves respectively for later use.

[0045] Based on 5% Er:Yb2W3O 12 Chemical formula: 2, 38, and 5 mL of 0.05 mol / L Er(NO3)3, Yb(NO3)3, and ammonium tungstate solution, respectively, were measured and placed in a beaker, and a mixed solution was obtained after magnetic stirring for 1 hour; 1.9212 g of citric acid was added to the mixed solution, and the solution was mixed and stirred at 110°C for 0.5 hour; thereafter, the pH value of the mixed solution was adjusted to 6 by dropwise addition of ammonia water, and a suspension was obtained after continuous stirring for 1.5 hours; the obtained suspension was transferred to a 110°C oven and kept warm for 3.5 hours to form a dry gel; the dry gel was placed in a pit furnace and calcined at 450°C for 2.5 hours to obtain a precursor; after the precursor was evenly ground, it was placed in a high-temperature sintering furnace, heated to 1000°C at a rate of 5°C / min, kept warm and calcined for 3 hours, cooled to room temperature with the furnace, and then ground for 15 minutes to obtain fluorescent nanocrystals for use;

[0046] Weigh 0.456g of glass powder that passed through a 100-mesh sieve and 0.024g of glass powder that passed through a 300-mesh sieve, stir and mix for 30 minutes, and then mix the glass powder with 0.02g of 5% Er:Yb2W3O 12 The mixture was ground and mixed in a mortar for 30 minutes. The powder was then loaded into a high-strength steel mold and pressed into a green blank with a diameter of about 13 mm using a uniaxial tablet press at a pressure of 300 MPa for 3 minutes. The green blank was placed in a box furnace and heated to 750°C at a heating rate of 5°C / min. After sintering for 15 minutes in an air atmosphere, the blank was cooled to room temperature in the furnace. Finally, the obtained glass body was mechanically processed and a fluorescent glass sheet with a thickness of 0.8 mm was obtained by grinding and polishing.

[0047] The obtained product was tested by up-conversion luminescence temperature spectrum. Under 980nm excitation, when the temperature gradually increased from room temperature to 573K, Er 3+ Ionic 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 The transitions were enhanced by 2.4 and 1.4 times respectively. 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 The relationship between the transition intensity ratio and temperature is used for fluorescence temperature sensing, and its highest relative sensitivity is 1.07%K at 298K. -1 .

[0048] Example 4

[0049] 2g of glass powder raw material was weighed according to the ratio of 70SiO2:7.7Al2O3:1.2CaO:1.5Na2CO3:0.8K2CO3:14H3BO3:0.8BaO:2MgO:2Yb2O3 (molar percentage), placed in a ZrO2 ball mill containing 20gZrO2 balls, and ball-milled on a planetary ball mill at a speed of 100rpm for 1h; the obtained mixed powder was placed in a corundum crucible, heated to 1600℃ and kept warm for 1h; the glass solution was quickly poured into water for rapid cooling, and after drying, the bulk glass was crushed and ground into powder in a mortar; the obtained powder was sieved through 100 and 300 mesh sieves respectively for later use;

[0050] Based on 2%Tm:Yb2Mo3O 12Chemical formula, 0.8, 39.2, and 8.6 mL of 0.05 mol / L Tm(NO3)3, Yb(NO3)3, and ammonium molybdate solution were measured and placed in a beaker, and a mixed solution was obtained after magnetic stirring for 1 hour; 1.9212 g of citric acid was added to the mixed solution, and the mixture was stirred at 100°C for 1 hour; thereafter, the pH value of the mixed solution was adjusted to 6 by dropwise addition of ammonia water, and a suspension was obtained after stirring for 1.5 hours; the obtained suspension was transferred to a 110°C oven and kept warm for 3.5 hours to form a dry gel; the dry gel was placed in a pit furnace and calcined at 500°C for 2.5 hours to obtain a precursor; after the precursor was evenly ground, it was placed in a high-temperature sintering furnace, heated to 1000°C at a rate of 5°C / min, kept warm and calcined for 3 hours, cooled to room temperature with the furnace, and ground for 15 minutes to obtain fluorescent nanocrystals for use;

[0051] Weigh 0.4704g of glass powder that passed through a 100-mesh sieve and 0.0145g of glass powder that passed through a 300-mesh sieve, stir and mix for 30 minutes, and then mix the glass powder with 0.015g of 2% Tm:Yb2Mo3O 12 The mixture was ground and mixed in a mortar for 30 minutes. The mixed powder was then loaded into a high-strength steel mold and pressed into a green blank with a diameter of about 13 mm using a uniaxial tablet press at a pressure of 400 MPa for 2 minutes. The green blank was placed in a box furnace and heated to 750°C at a heating rate of 5°C / min. After sintering for 10 minutes in an air atmosphere, the blank was cooled to room temperature in the furnace. Finally, the obtained glass body was mechanically processed and a fluorescent glass sheet with a thickness of 0.8 mm was obtained by grinding and polishing.

[0052] The obtained product was tested by up-conversion luminescence temperature spectrum. Under 980nm excitation, when the temperature was raised from room temperature to 573K, Tm 3+ Ionic 3 F 2,3 → 3 H6 and 3 H4→ 3 The H6 transition was enhanced by 9.0 and 2.17 times, respectively. 3+ The thermally coupled energy level pair of 3 F 2,3 → 3 H6 and 3 H4→ 3 The relationship between the H6 transition intensity ratio and temperature is used for fluorescence temperature sensing, and its highest relative sensitivity is 2.40%K at 298K. -1 .

Claims

1. A fluorescent thermally enhanced ceramic glass, which is a composite material of rare earth ion-doped fluorescent nanocrystals distributed in a glass matrix; characterized in that: Rare earth ion doped fluorescent nanocrystals are composed of xLn: Yb2M3O 12 , where Ln is Nd 3+ , Er 3+ or Tm 3 + M is one of W or Mo; the Ln doping concentration is x = 2~10mol%; the glass matrix is ​​made of the following raw materials: SiO2: 66~70mol%, Al2O3: 6~8mol%, CaO: 0.5~1.2mol%, Na2CO3: 1.5~2.5mol%, K2CO3: 0.5~0.8mol%, H3BO3: 11.7~14mol%, BaO: 0.3~0.8mol%, MgO: 2~4mol%, Yb2O3: 2~3mol%, the total molar amount of the above components is 100mol%.

2. The fluorescent heat-enhanced ceramic glass according to claim 1, characterized in that: The mass fraction of the nanocrystals in the ceramic glass is 3-5%.

3. The method for preparing fluorescent heat-enhanced ceramic glass according to claim 1, wherein: The method comprises three steps: preparing glass material by a rapid cooling method, preparing fluorescent nanocrystals by a sol-gel method, and mixing and co-sintering the glass material and the nanocrystals.

4. The method for preparing fluorescent heat-enhanced ceramic glass according to claim 3, characterized in that: The steps are as follows: (1) placing SiO2, Al2O3, CaO, Na2CO3, K2CO3, H3BO3, MgO, BaO, and Yb2O3 glass raw materials in a ZrO2 ceramic jar and loading ZrO2 ceramic balls; placing the ball mill jar in a ball mill, mixing the materials, placing the obtained mixed powder in a corundum crucible, and melting the mixture in a lifting furnace at 1500-1650°C for 0.5-1.2 hours; taking out the crucible, pouring the melt into water for rapid cooling; drying the obtained glass body, and then crushing and grinding it into powder in a mortar; passing the obtained powder through 100 and 300 mesh sieves respectively to obtain two glass powders with different particle size distributions for use; (2) Prepare various solutions according to the chemical formula of fluorescent nanocrystals, namely, take Ln(NO3)3, Yb(NO3)3, ammonium molybdate or ammonium tungstate powder and stir them in deionized water until they are completely dissolved to obtain the corresponding solutions for use; 12 According to the stoichiometric ratio, various solutions are measured, mixed in a beaker, and magnetically stirred for 1 hour to obtain a mixed solution; an organic complexing agent is added to the mixed solution so that the molar ratio of the total amount of metal cations in the solution to the complexing agent is 1:2, and the mixture is stirred at 60-90°C for 0.5-1 hour; then, the pH value of the mixed solution is adjusted to 5.5-6.5 by dropwise addition of ammonia water, and after stirring for 1-1.5 hours, a suspension is obtained; the obtained suspension is transferred to an oven and kept at 100-120°C for 3-4 hours to form a dry gel; the obtained dry gel is placed in a corundum crucible, placed in a pit furnace, and calcined at 400-550°C for 2-3 hours to obtain a precursor; after the precursor is evenly ground, it is placed in a high-temperature sintering furnace and calcined at 950-1100°C for 2-4 hours; it is cooled to room temperature with the furnace and then ground to obtain nanocrystals for use; (3) The glass powders passed through a 100-mesh sieve and a 300-mesh sieve obtained in the above step (1) are mixed in a mass ratio of 95-97:5-3, and ground in a mortar for 30 minutes; the obtained glass powder is mixed with the nanocrystals obtained in step (2), stirred in a mortar for 30 minutes, and then loaded into a high-strength steel mold, and pressed into a blank by a uniaxial tablet press at a pressure of 300-400 MPa for 2-3 minutes; the blank is placed in a box furnace, heated to 700-750°C, sintered at this temperature for 10-20 minutes, and then cooled to room temperature with the furnace; finally, the obtained glass body is subjected to surface fine grinding and polishing to obtain a ceramic glass sheet.

5. The method for preparing fluorescent heat-enhanced ceramic glass according to claim 4, characterized in that: In step (2), the organic complexing agent is any one of glycine and citric acid.

6. The method for preparing fluorescent heat-enhanced ceramic glass according to claim 4, characterized in that: The fluorescent nanocrystals prepared in step (2) are orthorhombic Yb2M3O with negative thermal expansion characteristics. 12 , where Ln 3+ As activator, Yb 3+ It is a sensitizer; the average grain size of the nanocrystals is 50~60nm.

7. The fluorescent thermal enhancement effect of the ceramic glass according to claim 4, characterized in that: When the temperature rises from room temperature to 573K, the rare earth ions Ln doped in the material 3+ The intensity of the emitted upconversion fluorescence continued to increase.

8. Use of the fluorescent heat-enhanced ceramic glass according to claim 1 in the field of temperature measurement.

9. The use of the fluorescent heat-enhanced ceramic glass according to claim 8 in the field of temperature measurement, characterized in that: By utilizing the relationship between the upconversion fluorescence intensity ratio of two thermally coupled energy levels in rare earth ions and temperature, non-contact temperature sensing from room temperature to 573K is achieved.

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