Fluorescent temperature measurement material, preparation method and application thereof, and fluorescent thermometer

Abstract

The invention discloses a fluorescent temperature measurement material, a preparation method and application thereof and a fluorescent thermometer, and relates to the technical field of luminescent materials, the chemical formula of the fluorescent temperature measurement material is Li < 1 + x > Ga < 5-x > O < 8-x >, x =-0.05-0.1, and x is not equal to 0. The fluorescent temperature measurement material provided by the invention can emit fluorescence in a blue light wave band and a red light wave band, and emission peaks of different wave bands of the fluorescent temperature measurement material have different dependency relationships on temperature changes. In the range of 220-360 K, along with the rise of the temperature, the fluorescence intensity of the blue light wave band is gradually weakened, and the fluorescence intensity of the red light wave band is gradually enhanced, so that the temperature in the range of 220-360 K can be measured according to the fluorescence intensity ratio of the two wave bands, and the relative sensitivity exceeds 4% K <-1 >. The fluorescent temperature measurement material is a ratio type fluorescent temperature measurement material, and is high in sensitivity, wide in applicable temperature range and good in stability when being used for temperature measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a fluorescent temperature measuring material, a preparation method and application thereof, and a fluorescent thermometer. Background Art

[0002] Temperature, as a physical parameter, is one of the most commonly measured physical quantities in industrial production and scientific research, making temperature sensing play an important role in various fields. Compared with traditional temperature sensors, optical temperature sensors have the advantages of fast readout speed, wide temperature range, suitable for non-contact measurement, small size application and harsh environment (such as highly corrosive environment, etc.). Optical temperature sensors measure temperature through changes in optically related parameters, including fluorescence intensity ratio (FIR), life, intensity, polarization, bandwidth and spectral position. Among them, the FIR-based temperature measurement method has become the preferred choice due to its fast readout speed, low cost, and most importantly, accurate readings and no influence from fluctuations in energy change excitation sources, and has a broad application space.

[0003] FIR type fluorescence thermometer materials can be used to evaluate the performance of fluorescence thermometers by calculating absolute sensitivity and relative sensitivity. Relative sensitivity can be used to compare the performance of different temperature measurement systems. 3+ , Tm 3+ , Ho 3+ , Nd 3+ and Eu 3+ ) is realized by the thermal coupling energy level, and its energy level difference is small, generally around 200cm -1 Up to 2000cm -1 In this case, the relative sensitivity rarely exceeds 2% K. -1 The fluorescence thermometer is difficult to meet the sensitivity requirements in practical applications. In addition, the optimal temperature measurement range of many existing FIR temperature measurement materials is in an uncommon temperature range, which further increases the application limitations of existing materials.

[0004] Therefore, it is urgent to develop a new FIR type temperature measurement material with high temperature measurement sensitivity and strong universality of applicable temperature range to make up for the application defects of existing temperature measurement materials.

[0005] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0006] Based on the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a fluorescent temperature measuring material, a preparation method and application thereof, and a fluorescent thermometer, aiming to provide a temperature measuring material with high temperature measurement sensitivity and strong universality of applicable temperature range, so as to make up for the application defects of existing temperature measuring materials.

[0007] The technical solution of the present invention is as follows:

[0008] In a first aspect of the present invention, a fluorescent temperature measuring material is provided, wherein the chemical formula of the fluorescent temperature measuring material is Li 1+x Ga 5-x O 8-x , where x=-0.05~0.1, and x is not equal to 0.

[0009] A second aspect of the present invention provides a method for preparing the fluorescent temperature measuring material as described above, comprising the following steps:

[0010] According to Li 1+x Ga 5-x O 8-x The lithium-containing compound and Ga2O3 are mixed according to the stoichiometric ratio of each element to obtain a mixture;

[0011] The fluorescent temperature measuring material is obtained by sintering the mixture.

[0012] Optionally, the lithium-containing compound includes at least one of Li2CO3, Li2O, and LiOH.

[0013] Optionally, the step of mixing the lithium-containing compound with Ga2O3 to obtain a mixture specifically includes:

[0014] The lithium-containing compound is mixed with Ga2O3 and ethanol, and then ground, and a mixture is obtained after the ethanol is evaporated.

[0015] Optionally, the sintering temperature condition is:

[0016] After raising the temperature from room temperature to 600-800°C, maintain it for 2-4 hours; then continue to raise the temperature to 1250-1300°C and maintain it for 4-5 hours.

[0017] Optionally, the sintering atmosphere is an air atmosphere.

[0018] The third aspect of the present invention provides an application of the fluorescent temperature measuring material as described above in the present invention and / or the fluorescent temperature measuring material prepared by the preparation method as described above in the present invention in the field of temperature measurement.

[0019] Optionally, the application method comprises the following steps:

[0020] The fluorescence emission spectra of the fluorescent temperature measuring material at different temperatures are measured to obtain the FIR at each temperature; wherein, at a certain temperature I a represents the fluorescence intensity in the a-nanometer band, I b represents the fluorescence intensity in b nanometer band;

[0021] Taking temperature as the independent variable and FIR as the dependent variable, after fitting, the relationship between FIR and temperature is obtained;

[0022] The fluorescent temperature measuring material is placed in the environment to be measured or on the surface of the object to be measured, the fluorescence intensity of the two bands a nanometer and b nanometer is measured, the FIR value is calculated, and the relationship between the FIR and the temperature obtained by the above fitting is substituted into the relationship between the FIR and the temperature to obtain the temperature of the environment to be measured or the temperature of the object to be measured.

[0023] Optionally, the temperature range measured by the fluorescent temperature measuring material is 220-360K.

[0024] A fourth aspect of the present invention provides a fluorescence thermometer, which comprises the fluorescence temperature measuring material of the present invention as described above and / or the fluorescence temperature measuring material prepared by the preparation method of the present invention as described above.

[0025] Beneficial effects: The fluorescent temperature measuring material provided by the present invention can emit fluorescence in both the blue light band and the red light band, and the emission peaks of the fluorescent temperature measuring material in different bands have different dependencies on temperature changes. In the range of 220-360K, as the temperature rises, the fluorescence intensity of the blue light band gradually weakens, and the fluorescence intensity of the red light band gradually increases. Therefore, the temperature in the range of 220-360K can be measured based on the fluorescence intensity ratio of the two bands, and in the temperature range of 260-360K, the relative sensitivity exceeds 4%K. -1 The fluorescent temperature measuring material is a ratiometric fluorescent temperature measuring material, which has high sensitivity, a wide applicable temperature range and good stability when used for temperature measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 XRD pattern of powder.

[0027] Figure 2 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 SEM image of powder.

[0028] Figure 3 is the Li prepared in Example 1 1.08 Ga4.92 O 7.92 Room temperature fluorescence spectrum of the powder.

[0029] Figure 4 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 Variable temperature fluorescence spectrum of the powder in the temperature range of 220~360K.

[0030] Figure 5 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 Fitting curve of the fluorescence emission peak intensity ratio of the powder in the temperature range of 220~360K and temperature.

[0031] Figure 6 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 Powder based on FIR(I 718 / I 400 ) absolute sensitivity S a curve.

[0032] Figure 7 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 Powder based on FIR(I 718 / I 400 )'s relative sensitivity S r curve.

[0033] Figure 8 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 The powder FIR (I 718 / I 400 ) value stability curve.

[0034] Fig. 9 is the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 Thermogravimetric curve of the powder. DETAILED DESCRIPTION

[0035] The present invention provides a fluorescent temperature measuring material and a preparation method and application thereof and a fluorescent thermometer. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] The embodiment of the present invention provides a fluorescent temperature measuring material, wherein the chemical formula of the fluorescent temperature measuring material is Li 1+ x Ga 5-x O 8-x , where x=-0.05~0.1, and x is not equal to 0.

[0038] The fluorescent temperature measuring material provided by the embodiment of the present invention can emit fluorescence in both the blue light band and the red light band, and the emission peaks of the fluorescent temperature measuring material in different bands have different dependencies on temperature changes. In the range of 220 to 360K, as the temperature increases, the fluorescence intensity of the blue light band gradually weakens, and the fluorescence intensity of the red light band gradually increases. Therefore, the temperature in the range of 220 to 360K can be measured based on the fluorescence intensity ratio of the two bands, and in the temperature range of 260 to 360K, the relative sensitivity exceeds 4%K. -1 The fluorescent temperature measuring material is a ratiometric fluorescent temperature measuring material, which has high sensitivity, a wide applicable temperature range and good stability when used for temperature measurement (the fluorescent temperature measuring material has stable chemical properties and is not significantly affected by multiple high and low temperature cycle tests, humid environments, and organic environments. It also has high temperature resistance and maintains good stability at 550°C).

[0039] In some embodiments, x is -0.05, -0.04, -0.03, -0.02, -0.01, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.1, and accordingly, the fluorescent temperature measuring material is Li 0.95 Ga 5.05 O 8.05 , Li 0.96 Ga 5.04 O 8.04 , Li 0.97 Ga 5.03 O 8.03 , Li 0.98 Ga 5.02 O 8.02 , Li 0.99 Ga 5.01 O 8.01 , Li 1.01 Ga 4.99 O 7.99 , Li1.02 Ga 4.98 O 7.98 , Li 1.03 Ga 4.97 O 7.97 , Li 1.04 Ga 4.96 O 7.96 , Li 1.05 Ga 4.95 O 7.95 , Li 1.06 Ga 4.94 O 7.94 , Li 1.07 Ga 4.93 O 7.93 , Li 1.08 Ga 4.92 O 7.92 , Li 1.09 Ga 4.91 O 7.91 or Li 1.10 Ga 4.90 O 7.90 wait.

[0040] In this embodiment, the crystal phase of the fluorescent thermometric material (i.e., lithium gallium oxide) is an inverse spinel structure, and the space group is P4332. These fluorescent thermometric materials can emit fluorescence at both 400nm and 718nm under the irradiation of a 254nm excitation source, wherein the emission peak at 400nm belongs to the blue light band and broadband emission, and the emission peak at 718nm belongs to the red light band and narrowband sharp line emission. In other words, under 254nm excitation, the fluorescent thermometric material has strong emission in both the blue light band (centered at 400nm) and the red light band (centered at 718nm), specifically because Li 1+x Ga 5-x O 8-x The crystal has an inverse spinel structure, and a large number of defects will be generated during the preparation process. In addition, the substitution of Li atoms and Ga atoms further increases the degree of disorder, resulting in more defects such as oxygen vacancies. These intrinsic defects lead to the self-activation effect of the [GaO4] structure inside the crystal, resulting in a broadband emission of blue light centered at 400nm. On the other hand, by regulating the content of lithium, the defects and trap energy levels inside the crystal are further enriched. These newly added trap energy levels induce Li + Intra-ion transition 2 S→ 2 P0, resulting in a narrow-band sharp-line emission centered at 718nm.

[0041] The embodiment of the present invention further provides a method for preparing the fluorescent temperature measuring material of the present invention as described above, wherein the method comprises the following steps:

[0042] S11. According to Li 1+x Ga 5-x O 8-x The lithium-containing compound and Ga2O3 are mixed according to the stoichiometric ratio of each element to obtain a mixture;

[0043] S12, sintering the mixture to obtain the fluorescent temperature measuring material.

[0044] The embodiment of the present invention directly prepares the fluorescent temperature measuring material by a high-temperature solid-phase synthesis method. The synthesis method is simple and fast, does not require a harsh gas environment, has low equipment requirements, and is low in cost. The prepared fluorescent temperature measuring material has excellent purity and crystallinity.

[0045] In some embodiments, the lithium-containing compound includes at least one of Li2CO3, Li2O, and LiOH, but is not limited thereto.

[0046] In some embodiments, the step of mixing the lithium-containing compound with Ga2O3 to obtain a mixture specifically includes:

[0047] The lithium-containing compound is mixed with Ga2O3 and ethanol, and then ground, and a mixture is obtained after the ethanol is volatilized.

[0048] In some embodiments, the sintering temperature conditions are:

[0049] After raising the temperature from room temperature to 600-800°C (for example, 600°C, 650°C, 700°C, 750°C or 800°C, etc.), maintain it for 2-4h (for example, 2h, 2.5h, 3h, 3.5h or 4h, etc.); then continue to raise the temperature to 1250-1300°C (for example, 1250°C, 1260°C, 1270°C, 1280°C, 1290°C or 1300°C, etc.), maintain it for 4-5h (for example, 4h, 4.1h, 4.2h, 4.3h, 4.4h, 4.5h, 4.6h, 4.7h, 4.8h, 4.9h or 5h, etc.).

[0050] The sintering conditions combined with the regulation of lithium content further enriched the defects and trap levels inside the crystal. These newly added trap levels induced Li + Intra-ion transition 2 S→ 2 P0, resulting in a narrow-band sharp-line emission centered at 718nm.

[0051] In some embodiments, the sintering is carried out in an air atmosphere.

[0052] An embodiment of the present invention further provides an application of the fluorescent temperature measuring material as described above in the field of temperature measurement.

[0053] The embodiment of the present invention further provides an application of a fluorescent temperature measuring material prepared by the preparation method of the present invention as described above in the field of temperature measurement.

[0054] The embodiments of the present invention further provide an application of the fluorescent temperature measuring material as described above and the fluorescent temperature measuring material prepared by the preparation method as described above in the field of temperature measurement.

[0055] In some embodiments, the method of application comprises the following steps:

[0056] S21, measuring the fluorescence emission spectra of the fluorescent temperature measuring material at different temperatures to obtain the FIR at each temperature; wherein, at a certain temperature I a represents the fluorescence intensity in the a-nanometer band, I b represents the fluorescence intensity in b nanometer band;

[0057] S22, taking temperature as the independent variable and FIR as the dependent variable, after fitting, the relationship between FIR and temperature is obtained;

[0058] S23, placing the fluorescent temperature measuring material in the environment to be measured or on the surface of the object to be measured, measuring the fluorescence intensity of the two bands a nanometer and b nanometer, calculating the FIR value, and substituting it into the relationship between the FIR and temperature obtained by the above fitting to obtain the temperature of the environment to be measured or the temperature of the object to be measured.

[0059] In this embodiment, the functional relationship between the FIR and temperature of the fluorescent temperature measuring material is first determined, and then when it is used to measure the temperature of the environment to be measured or the temperature of the object to be measured, the FIR value obtained by measurement is substituted into the above functional relationship to obtain the temperature of the environment to be measured or the temperature of the object to be measured.

[0060] In step S21, in some specific embodiments, a=400, b=718, that is, under the irradiation of an excitation source of 254 nm, the fluorescence emission spectra of the fluorescent temperature measuring material at different temperatures are measured to obtain the FIR at each temperature; wherein, at a certain temperature I 400 Represents the fluorescence intensity in the 400nm band, I 718 It represents the fluorescence intensity in the 718 nm band.

[0061] In step S22, in some embodiments, the discrete points of FIR at each temperature conform to the Boltzmann distribution, and the relationship between the fitted FIR and temperature is:

[0062]

[0063] Among them, A, B, C are constants, and T represents temperature.

[0064] In addition, the absolute sensitivity S at different temperatures is calculated a and relative sensitivity S r , and draw a curve. The calculation formula is:

[0065]

[0066]

[0067] It is calculated that in the temperature range of 260-360K, the relative sensitivity exceeds 4%K -1 , and the relative sensitivity reaches a maximum value of 9.7% K at 290 K -1 , which confirms that the fluorescent temperature measuring material has good sensitivity and the superiority of the fluorescent temperature measuring material in the application of FIR type fluorescence thermometer.

[0068] In some embodiments, the temperature range measured by the fluorescent thermometric material is 220-360K.

[0069] An embodiment of the present invention also provides a fluorescence thermometer (specifically a ratio-type fluorescence thermometer), which includes the fluorescence thermometric material of the present invention as described above, or includes the fluorescence thermometric material prepared by the preparation method of the present invention as described above, or includes the fluorescence thermometric material of the present invention as described above and the fluorescence thermometric material prepared by the preparation method of the present invention as described above.

[0070] The invention is based on the fluorescence intensity ratio temperature measurement technology and provides a ratio type fluorescence thermometer based on the fluorescence intensity ratio of the dual bands of the fluorescence temperature measurement material, which achieves significantly improved relative sensitivity and absolute sensitivity, and has a wide applicable temperature range and strong stability.

[0071] The present invention will be further described below by means of specific examples.

[0072] Example 1

[0073] This embodiment provides a fluorescent temperature measuring material (ie Li 1.08 Ga 4.92 O 7.92 The preparation method of powder) comprises the following steps:

[0074] (1) According to Li 1.08 Ga 4.92 O 7.92The stoichiometric ratio of each element in the mixture was determined by weighing 1.08 mmol of Li2CO3 (purity 99.99%) and 4.92 mmol of Ga2O3 (purity 99.99%), placing them in a mortar, adding an appropriate amount of anhydrous ethanol as a dispersant, grinding them evenly (30 min) and waiting for the ethanol to completely evaporate to obtain a mixture.

[0075] The above mixture was transferred into an alumina crucible (10 mL), and then placed in a tube furnace for sintering in an air atmosphere. The sintering conditions included two heating processes, specifically: the first stage was from room temperature to 800°C, and the temperature was kept constant for 2 h; the second stage was from 800°C to 1300°C, and the temperature was kept constant for 5 h, and then cooled to room temperature at a rate of 2°C / s;

[0076] The sintered product is ground again to obtain Li 1.08 Ga 4.92 O 7.92 powder.

[0077] test:

[0078] (1) The Li prepared in Example 1 1.08 Ga 4.92 O 7.92 The powder was subjected to X-ray diffraction (XRD) test, and the results were as follows Figure 1 As shown, Li 1.08 Ga 4.92 O 7.92 The diffraction peaks are completely consistent with the XRD standard card PDF#38-1371 of LiGa5O8 and have no impurity peaks or peak shifts, indicating good crystallinity and purity.

[0079] (2) Using an inductively coupled plasma mass spectrometer to test the Li obtained in Example 1 1.08 Ga 4.92 O 7.92 The element ratio of the powder is shown in Figure 1, where the molar ratio of the metal elements is Li:Ga=1.06:4.92, which is basically consistent with the original feed ratio.

[0080] Table 1. Inductively coupled plasma mass spectrometer test results

[0081]

[0082] (3) The Li prepared in Example 1 1.08 Ga 4.92 O 7.92 The powder was tested by scanning electron microscope (SEM). Figure 2 As shown, the results show that the prepared product presents a rod-like structure with a length of about 2 microns and a diameter of about 1 micron.

[0083] (4) Test the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 The room temperature fluorescence spectrum of the powder is shown in Figure 3 As shown in the figure, it can be seen that under the excitation light source with a wavelength of 254nm, the obtained fluorescence spectrum includes two emission peaks with comparable absolute intensities. One is a broadband emission in the blue light band centered at 400nm, corresponding to the self-activation effect of oxygen vacancies and [GaO4] structure; the other is a narrow-band sharp line emission in the red light band centered at 718nm, corresponding to Li + Intra-ion transition 2 S→ 2 P0.

[0084] (5) Test the Li prepared in Example 1 1.08 Ga 4.92 O 7.92 The temperature-dependent fluorescence spectrum of the powder in the temperature range of 220 to 360 K is as follows: Figure 4 As shown, the wavelength of the excitation light source is 254nm, and the fluorescence spectra at 220K, 230K, 240K, 250K, 260K, 270K, 280K, 290K, 300K, 310K, 320K, 330K, 340K, 350K and 360K are tested respectively. The results show that with the increase of temperature, the fluorescence intensity of the blue light band (centered at 400nm) gradually weakens, and the fluorescence intensity of the red light band (centered at 718nm) gradually increases, showing a trend of one increasing and the other decreasing.

[0085] (6) Sensitivity analysis of ratio-based temperature measurement method

[0086] According to the FIR technology and the above-mentioned variable temperature fluorescence spectrum, the FIR (I 718 / I 400 ) value and perform curve fitting, such as Figure 5 As shown, the fitting curve is:

[0087] R 2 =0.9985, indicating a good fit.

[0088] Furthermore, based on FIR(I 718 / I 400 ) and fitting curves, calculate and plot the absolute sensitivity S at different temperatures a and relative sensitivity S r The change curve of Figure 6 and Figure 7 The above results prove that Li 1.08 Ga 4.92 O 7.92It is highly applicable in ratiometric fluorescence temperature measurement and has excellent high sensitivity. In the temperature range of 260-360K, the relative sensitivity exceeds 4%K -1 , and the relative sensitivity reaches a maximum value of 9.7% K at 290 K -1 Among them, S a and S r The value of is obtained by the following formula:

[0089]

[0090]

[0091] (7) Repeatability and stability test

[0092] The temperature was raised and lowered from the lowest temperature of 220K to the highest temperature of 360K in a cycle, and the fluorescence emission spectrum was recorded by a fluorescence spectrometer. The fluorescence intensity ratio of the red light band and the blue light band was calculated to test the Li 1.08 Ga 4.92 O 7.92 The stability in practical applications is shown in the following results. Figure 8 As shown in Figure 2, the fluctuation of FIR values ​​at 220K, 290K and 360K during 10 low-temperature-high-temperature cycle tests proves that Li 1.08 Ga 4.92 O 7.92 The ratiometric fluorescence temperature measurement method has good stability and anti-aging properties.

[0093] Thermogravimetric test, at a temperature of 800 ° C, such as Fig. 9 As shown, the Li obtained in Example 1 1.08 Ga 4.92 O 7.92 The powder quality can still maintain 98.3%, showing good thermal stability.

[0094] Example 2

[0095] This embodiment provides a fluorescent temperature measurement material (ie, Li 0.95 Ga 5.05 O 8.05 The preparation method of powder) comprises the following steps:

[0096] (1) According to Li 0.95 Ga 5.05 O 8.05 The stoichiometric ratio of each element in the mixture is determined by weighing 0.95 mmol of Li2CO3 (purity of 99.99%) and 5.05 mmol of Ga2O3 (purity of 99.99%), placing them in a mortar, and adding an appropriate amount of anhydrous ethanol as a dispersant. After grinding evenly and waiting for the ethanol to completely evaporate, a mixture is obtained.

[0097] The mixture was transferred into an alumina crucible and then placed in a tube furnace for sintering in an air atmosphere. The sintering conditions included two heating processes: the first heating process was from room temperature to 800°C and kept at a constant temperature for 2 hours; the second heating process was from 800°C to 1300°C and kept at a constant temperature for 5 hours, and then cooled to room temperature at a rate of 2°C / s.

[0098] The sintered product is ground again to obtain Li 0.95 Ga 5.05 O 8.05 powder.

[0099] Example 3

[0100] This embodiment provides a fluorescent temperature measuring material (ie Li 1.01 Ga 4.99 O 7.99 The preparation method of powder) comprises the following steps:

[0101] (1) According to Li 1.01 Ga 4.99 O 7.99 The stoichiometric ratio of each element in the mixture is determined by weighing 1.01 mmol of Li2CO3 (purity of 99.99%) and 4.99 mmol of Ga2O3 (purity of 99.99%), placing them in a mortar, and adding an appropriate amount of anhydrous ethanol as a dispersant. After grinding evenly and waiting for the ethanol to completely evaporate, a mixture is obtained.

[0102] The mixture was transferred into an alumina crucible and then placed in a tube furnace for sintering in an air atmosphere. The sintering conditions included two heating processes: the first heating process was from room temperature to 800°C and kept at a constant temperature for 2 hours; the second heating process was from 800°C to 1300°C and kept at a constant temperature for 5 hours, and then cooled to room temperature at a rate of 2°C / s.

[0103] The sintered product is ground again to obtain Li 1.01 Ga 4.99 O 7.99 powder.

[0104] Example 4

[0105] This embodiment provides a fluorescent temperature measuring material (ie Li 1.1 Ga 4.9 O 7.9 The preparation method of powder) comprises the following steps:

[0106] (1) According to Li 1.1 Ga 4.9 O 7.9The stoichiometric ratio of each element in the mixture is determined by weighing 1.1 mmol of Li2CO3 (purity 99.99%) and 4.9 mmol of Ga2O3 (purity 99.99%), placing them in a mortar, and adding an appropriate amount of anhydrous ethanol as a dispersant. After grinding evenly and waiting for the ethanol to completely evaporate, a mixture is obtained.

[0107] The mixture was transferred into an alumina crucible and then placed in a tube furnace for sintering in an air atmosphere. The sintering conditions included two heating processes: the first heating process was from room temperature to 800°C and kept at a constant temperature for 2 hours; the second heating process was from 800°C to 1300°C and kept at a constant temperature for 5 hours, and then cooled to room temperature at a rate of 2°C / s.

[0108] The sintered product is ground again to obtain Li 1.1 Ga 4.9 O 7.9 powder.

[0109] The fluorescent thermometric materials in Examples 2 to 4 were subjected to XRD testing, SEM testing, variable temperature fluorescence spectroscopy in the temperature range of 220 to 360 K, and sensitivity analysis of the ratiometric thermometry method. The results showed that the fluorescent thermometric materials in Examples 2 to 4 had similar properties to the fluorescent thermometric material in Example 1.

[0110] In summary, the present invention provides a fluorescent temperature measuring material, a preparation method and application thereof, and a fluorescent thermometer. The fluorescent temperature measuring material can emit fluorescence in both the blue light band and the red light band, and the emission peaks of the fluorescent temperature measuring material in different bands have different dependencies on temperature changes. In the range of 220 to 360K, as the temperature increases, the fluorescence intensity of the blue light band gradually weakens, and the fluorescence intensity of the red light band gradually increases. Therefore, the temperature in the range of 220 to 360K can be measured based on the fluorescence intensity ratio of the two bands, and in the temperature range of 260 to 360K, the relative sensitivity exceeds 4%K. -1 The fluorescent temperature measuring material is a ratiometric fluorescent temperature measuring material, which has high sensitivity, a wide applicable temperature range and good stability when used for temperature measurement.

[0111] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A fluorescent temperature measuring material, characterized in that: The chemical formula of the fluorescent temperature measuring material is Li 1+x Ga 5-x O 8-x , where x=-0.05~0.1, and x is not equal to 0.

2. A method for preparing the fluorescent temperature measuring material according to claim 1, characterized in that: The steps include: According to Li 1+x Ga 5-x O 8-x The lithium-containing compound and Ga2O3 are mixed according to the stoichiometric ratio of each element to obtain a mixture; The fluorescent temperature measuring material is obtained by sintering the mixture.

3. The preparation method according to claim 2, characterized in that: The lithium-containing compound includes at least one of Li2CO3, Li2O, and LiOH.

4. The preparation method according to claim 2, characterized in that: The step of mixing the lithium-containing compound with Ga2O3 to obtain a mixture specifically comprises: The lithium-containing compound is mixed with Ga2O3 and ethanol, and then ground, and a mixture is obtained after the ethanol is evaporated.

5. The preparation method according to claim 2, characterized in that: The sintering temperature conditions are: After raising the temperature from room temperature to 600-800°C, maintain it for 2-4 hours; then continue to raise the temperature to 1250-1300°C and maintain it for 4-5 hours.

6. The preparation method according to claim 2, characterized in that: The sintering atmosphere is air atmosphere.

7. Use of the fluorescent temperature measuring material according to claim 1 and / or the fluorescent temperature measuring material prepared by the preparation method according to any one of claims 2 to 6 in the field of temperature measurement.

8. The use according to claim 7, characterized in that: The application method comprises the following steps: The fluorescence emission spectra of the fluorescent temperature measuring material at different temperatures are measured to obtain the FIR at each temperature; wherein, at a certain temperature I a represents the fluorescence intensity in the a-nanometer band, I b represents the fluorescence intensity in b nanometer band; Taking temperature as the independent variable and FIR as the dependent variable, after fitting, the relationship between FIR and temperature is obtained; The fluorescent temperature measuring material is placed in the environment to be measured or on the surface of the object to be measured, the fluorescence intensity of the two bands a nanometer and b nanometer is measured, the FIR value is calculated, and the relationship between the FIR and the temperature obtained by the above fitting is substituted into the relationship between the FIR and the temperature to obtain the temperature of the environment to be measured or the temperature of the object to be measured.

9. The use according to claim 7, characterized in that: The temperature range measured by the fluorescent temperature measuring material is 220-360K.

10. A fluorescence thermometer, characterized in that: It comprises the fluorescent temperature measuring material as claimed in claim 1 and / or the fluorescent temperature measuring material prepared by the preparation method as claimed in any one of claims 2 to 6.

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