A negative thermal expansion material phosphor and its preparation method and application

Abstract

The present invention discloses a negative thermal expansion material phosphor and its preparation method and application, which belongs to the field of temperature measurement. The method comprises: adding Eu2O3 and Tb4O7 to a mixture of Y2O3 and MoO3, adding ethanol and grinding to obtain mixed materials A and mixed materials B; then calcining them to obtain Y2Mo3O 12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor; Y2Mo3O 12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor powder is mixed and ground to obtain negative thermal expansion material phosphor powder. 12 As a matrix, red and green light emission is obtained by single doping Eu and Tb. Thermal enhancement is achieved by energy transfer with Eu and thermal quenching of Tb is achieved to increase the relative intensity ratio. Using 295nm light excitation, the phosphor is heated from 20℃ to 300℃. By regulating the change of fluorescence intensity with temperature, temperature measurement is achieved. The phosphor has strong dependence on temperature and high sensitivity, reaching a maximum absolute sensitivity of 2.56%K at 453K. ‑1 , can be used for temperature sensors.

Description

Technical Field

[0001] The invention belongs to the field of temperature measurement, and in particular relates to a negative thermal expansion material fluorescent powder and a preparation method and application thereof. Background Art

[0002] With the advancement of science and technology, the requirements for material performance in high-temperature environments are becoming increasingly stringent. In fields such as aerospace, energy, and electronics, materials must be able to maintain stable performance in high-temperature environments. Temperature sensing technology plays a vital role in industries such as industry, biomedicine, and environmental monitoring. Traditional temperature sensors often suffer from large size and slow response speed. To address these issues, research has recently begun on novel temperature sensing materials. Therefore, the use of negative thermal expansion (NTE) phosphors has become a hot research topic. NTE materials exhibit negative linear thermal expansion at high temperatures, with their linear thermal expansion coefficient decreasing with increasing temperature. This property makes NTE materials valuable for applications in certain specialized fields. The use of NTE phosphors combines the properties of these two materials, resulting in a negative thermal expansion property. This combination allows phosphors to maintain stable performance in high-temperature environments, making them even more useful in specialized applications. By measuring the fluorescence intensity of phosphors at different temperatures, studying the correlation between fluorescence intensity and temperature, and determining the temperature sensitivity of the phosphors, it is possible to detect external temperature changes. Temperature sensing technology plays a vital role in industries such as industry, biomedicine, and environmental monitoring. Currently, most of the temperature sensing using negative thermal expansion material phosphors focuses on detecting the sensitivity of the phosphors to temperature by detecting the intensity change of the phosphors. However, the temperature can only be characterized by detecting the fluorescence intensity of a single luminescent center phosphor, which has certain limitations. Summary of the Invention

[0003] In view of the above shortcomings of the prior art, the present invention provides a negative thermal expansion material phosphor and a preparation method and application thereof.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a negative thermal expansion material phosphor comprises:

[0005] (1) Eu2O3 and Tb4O7 were added to a mixture of Y2O3 and MoO3, respectively, and ethanol was added and ground to obtain mixed materials A and B;

[0006] (2) Mixture A and mixture B are calcined separately to obtain Y2Mo3O 12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor;

[0007] (3) Y2Mo3O12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor powder is mixed and ground in a molar ratio of 1:1 to obtain negative thermal expansion material phosphor powder.

[0008] As a preferred embodiment of the present invention, the molar ratio of Eu2O3, Y2O3 and MoO3 is 0.02:0.98:3.00.

[0009] As a preferred embodiment of the present invention, the molar ratio of Tb4O7, Y2O3 and MoO3 is 0.0375:0.9250:3.0000.

[0010] As a preferred embodiment of the present invention, the calcination temperature is 850° C., the time is 6 hours, the heating rate is 5° C. / min, and the atmosphere is air.

[0011] As a preferred embodiment of the present invention, the grinding time is 10 minutes.

[0012] The present invention also claims to protect the negative thermal expansion material phosphor Y2Mo3O prepared by the preparation method of the negative thermal expansion material phosphor 12 :Eu / Tb.

[0013] The present invention also claims protection for the application of the negative thermal expansion material phosphor in a temperature sensor.

[0014] Compared with the prior art, the present invention has the following advantages: 12 As a matrix, red and green light emission is obtained by single doping Eu and Tb. Due to the negative thermal expansion effect, Eu and the matrix Y2Mo3O 12 The energy transfer between Tb and the matrix Y2Mo3O is more efficient and faster, which enhances the red light emission of Eu. 12 There is no energy transfer between the two, which reduces the green light emission of Tb. Therefore, by 12 :Eu and Y2Mo3O 12 The mixture of 2:1 and 2:1 Tb can achieve the regulation of luminescent color. Using a 295nm ultraviolet lamp as the excitation light source, the phosphor is heated from 20℃ to 300℃. The temperature is measured by adjusting the fluorescence intensity to compare the temperature change. The phosphor has a strong dependence on temperature and high sensitivity. The maximum absolute sensitivity is 2.56%K at 453K. -1 , can be used for temperature sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1Fluorescence spectra of the negative thermal expansion material phosphors prepared in Example 1, Comparative Examples 1 and 2 measured by an F7000 fluorescence spectrometer under excitation by a 295nm ultraviolet lamp at temperatures of 20°C, 60°C, 100°C, 140°C, 180°C, 220°C, 260°C and 300°C; (c) is the fluorescence spectrum of Example 1, (a) is the fluorescence spectrum of Comparative Example 1, and (b) is the fluorescence spectrum of Comparative Example 2.

[0016] Figure 2 Fluorescence spectra of the negative thermal expansion material phosphors prepared in Example 1, Comparative Examples 1 and 2 measured by F7000 fluorescence spectrometer Figure 1 The calculated fluorescence intensity ratio is plotted against temperature; (c) is a plot of the fluorescence intensity ratio of Example 1 against temperature, (a) is a plot of the fluorescence intensity ratio of Comparative Example 1 against temperature, and (b) is a plot of the fluorescence intensity ratio of Comparative Example 2 against temperature.

[0017] Figure 3 The negative thermal expansion material phosphors prepared in Example 1, Comparative Examples 1 and 2 are Figure 2 The calculated temperature measurement sensitivity is plotted against temperature; (c) is a plot of the fluorescence sensitivity of Example 1 against temperature, (a) is a plot of the sensitivity of Comparative Example 1 against temperature, and (b) is a plot of the sensitivity of Comparative Example 2 against temperature. DETAILED DESCRIPTION

[0018] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0019] Example 1

[0020] A method for preparing a negative thermal expansion material phosphor comprises:

[0021] (1) 0.02 mol Eu2O3 and 0.0375 mol Tb4O7 were added to a mixture of 0.98 mol Y2O3 and 3.0 mol MoO3 and a mixture of 0.925 mol Y2O3 and 3.0 mol MoO3, respectively. Ethanol was added and ground to obtain mixture A and mixture B.

[0022] (2) Mixed materials A and B were placed in alumina crucibles and placed in a box furnace. Under air atmosphere, the temperature was raised to 850°C at a rate of 5°C / min and sintered for 6 hours. After cooling, Y2Mo3O 12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor.

[0023] (3) Y2Mo3O 12:Eu phosphor and Y2Mo3O 12 :Tb phosphor powder was put into a ceramic mortar at a molar ratio of 1:1 and ground for 10 minutes to obtain the desired negative thermal expansion material phosphor Y2Mo3O 12 :Eu / Tb.

[0024] The prepared negative thermal expansion material phosphor Y2Mo3O 12 :Eu / Tb as temperature measurement application:

[0025] (1) negative thermal expansion material phosphor Y2Mo3O 12 :Eu / Tb was heated at 20℃, 60℃, 100℃, 140℃, 180℃, 220℃, 260℃, and 300℃, and the results were obtained by using F7000 fluorescence spectrometer. Figure 1 (c) shows the fluorescence spectrum. From the spectrum, it can be seen that the fluorescence intensity of the green peak (550nm) gradually decreases with increasing temperature, and the red peak (617nm) gradually increases with increasing temperature, indicating that the fluorescence intensity is dependent on temperature. Therefore, temperature measurement can be performed based on the relationship between fluorescence intensity and temperature.

[0026] (2) Based on step (1), through I Eu / I Tb The temperature sensitivity is investigated by using the fluorescence intensity ratio (FIR), which satisfies the following relationship:

[0027]

[0028] Where, I T-Eu Y2Mo3O 12 : The luminous intensity of the red peak (617nm) of Eu / Tb at a temperature of (293-573)K, I T-Tb Y2Mo3O 12 : Luminous intensity of green peak (550nm) of Eu / Tb at temperature (293-573)K, I 0-Eu Y2Mo3O 12 : The luminous intensity of the red peak (617nm) of Eu / Tb at a temperature of 293K, I 0-Tb Y2Mo3O 12 : Luminous intensity of green peak (550nm) of Eu / Tb at 293K, A Eu 、A Tb is a constant, E Eu 、E Tb are the thermal quenching activation energies of Eu and Tb, respectively, which are constants, K B is the Boltzmann constant, and T is the real-time temperature.

[0029] (3) Substitute the fluorescence intensity data of green light 550nm and red light 617nm obtained in step (1) into formula (2) for data fitting and obtain the following: Figure 2 (c) The relationship between fluorescence intensity and temperature and the standard formula for the relationship between fluorescence intensity and temperature are shown as follows:

[0030]

[0031] Where B, C, and D are constants that can be obtained through nonlinear fitting, and their values ​​are 0.4893, 1935514.58, 6047.03, and K B is the Boltzmann constant, T is the real-time temperature;

[0032] from Figure 2 As can be seen in (c), each temperature point corresponds to a different fluorescence intensity ratio I Eu / I Tb , so the fluorescence intensity ratio I Eu / I Tb The temperature can be accurately known by the relationship diagram or relationship formula (2) and temperature measurement can be performed.

[0033] The absolute temperature sensitivity Sr is used to represent the rate of change of the FIR value with temperature, thereby verifying the feasibility of the material for temperature measurement:

[0034]

[0035] according to Figure 3 (c) It can be seen that the sensitivity in Example 1 first increases and then decreases with the increase of temperature, showing dependence on temperature. The maximum absolute sensitivity is 2.56% K at 453 K. -1 , which proves the feasibility and accuracy of the prepared material in temperature measurement and can be used in temperature sensors.

[0036] Comparative Example 1

[0037] A method for preparing a negative thermal expansion material phosphor comprises:

[0038] (1) Add 0.02 mol Eu2O3 to a mixture of 0.98 mol Y2O3 and 3.0 mol MoO3, add ethanol and grind to obtain a mixture A.

[0039] (2) Mixed material A is placed in an alumina crucible and placed in a box furnace. In an air atmosphere, the temperature is raised to 850°C at a heating rate of 5°C / min and sintered for 6 hours. After cooling, Y2Mo3O 12 :Eu phosphor.

[0040] The prepared negative thermal expansion material phosphor Y2Mo3O12 :Eu as a temperature measurement application:

[0041] (1) negative thermal expansion material phosphor Y2Mo3O 12 :Eu was heated at 20℃, 60℃, 100℃, 140℃, 180℃, 220℃, 260℃, and 300℃, and the results were obtained by using F7000 fluorescence spectrometer. Figure 1 As shown in the fluorescence spectrum, the red light peak intensity at 617nm and 707nm gradually increases with increasing temperature, and temperature measurement is performed based on the relationship between fluorescence intensity and temperature.

[0042] (2) Through I 617nm / I 707nm The temperature sensitivity is investigated by using the fluorescence intensity ratio (FIR), and the FIR satisfies the following relationship:

[0043]

[0044] Where, I T-617 Y2Mo3O 12 : The luminous intensity of the red peak (617nm) of Eu at a temperature of (293-573)K, I T-707 Y2Mo3O 12 : The luminous intensity of the red peak (707nm) of Eu at a temperature of (293-573)K, I 0-707 Y2Mo3O 12 : The luminous intensity of the red peak (707nm) of Eu at a temperature of 293K, I 0-617 Y2Mo3O 12 : The luminous intensity of the red peak (617nm) of Eu at a temperature of 293K, A 617 、A 707 is a constant, E 617 、E 707 is the thermal quenching activation energy of Eu, which is a constant, K B is the Boltzmann constant, and T is the real-time temperature.

[0045] (3) Substitute the fluorescence intensity data of red light 707nm and red light 617nm obtained in step (1) into formula (4) for data fitting to obtain the following: Figure 2 (a) shows the relationship between fluorescence intensity and temperature and the formula for the relationship between fluorescence intensity and temperature:

[0046]

[0047] Where B, C, and D are constants that can be obtained through nonlinear fitting, and their values ​​are 0.5467, 199.88, 2158.75, and K Bis the Boltzmann constant, T is the real-time temperature, -△E is a constant; Figure 2 As can be seen in (a), each temperature point corresponds to a different fluorescence intensity ratio, but Y2Mo3O 12 :Eu fluorescence intensity ratio I 617nm / I 707nm The temperature curves do not completely match, proving that its dependence on temperature is lower than that of the embodiment.

[0048] The absolute temperature sensitivity Sr is used to represent the rate of change of the FIR value with temperature, thereby verifying the feasibility of the material for temperature measurement:

[0049]

[0050] from Figure 2 (a) It can be seen that compared with Example 1, the material prepared in Comparative Example 1 is less sensitive to temperature.

[0051] Comparative Example 2

[0052] A method for preparing a negative thermal expansion material phosphor comprises:

[0053] (1) 0.0375 mol of Tb4O7 was added to a mixture of 0.925 mol of Y2O3 and 3.0 mol of MoO3, and ethanol was added and ground to obtain a mixture A.

[0054] (2) Mixed material A is placed in an alumina crucible and placed in a box furnace. In an air atmosphere, the temperature is raised to 850°C at a rate of 5°C / min and sintered for 6 hours. After cooling, Y2Mo3O 12 :Tb phosphor.

[0055] The prepared negative thermal expansion material phosphor Y2Mo3O 12 :Tb as a temperature measurement application:

[0056] (1) negative thermal expansion material phosphor Y2Mo3O 12 :Tb was heated at 20℃, 60℃, 100℃, 140℃, 180℃, 220℃, 260℃ and 300℃, and the results were obtained by using F7000 fluorescence spectrometer. Figure 1 As shown in the fluorescence spectrum, the green light peaks at 550nm and 497nm gradually decrease as the temperature increases, and temperature measurement is performed based on the relationship between fluorescence intensity and temperature.

[0057] (2) Through I 550nm / I 497nm The temperature sensitivity is investigated by using the fluorescence intensity ratio (FIR), and the FIR satisfies the following relationship:

[0058]

[0059] Where, I T-550 Y2Mo3O 12 : Luminous intensity of green peak (550nm) of Tb at temperature (293-573)K, I T-497 Y2Mo3O 12 : The luminous intensity of the green peak (497nm) of Tb at a temperature of (293-573)K, I 0-550 Y2Mo3O 12 : The luminous intensity of the green peak (550nm) of Tb at a temperature of 293K, I 0-497 Y2Mo3O 12 : The luminous intensity of the green peak (497nm) of Tb at a temperature of 293K, A 497 、A 550 is a constant, E 497 、E 550 is the thermal quenching activation energy, which is a constant, K B is the Boltzmann constant, and T is the real-time temperature.

[0060] (3) Substitute the fluorescence intensity data of green light 497nm and green light 550nm obtained in step (1) into formula (7) for data fitting and obtain the following: Figure 2 (b) shows the relationship between fluorescence intensity and temperature and the formula for the relationship between fluorescence intensity and temperature:

[0061]

[0062] Where B, C, and D are constants that can be obtained through nonlinear fitting, and their values ​​are -336.37, 336.17, -1.16, and K B is the Boltzmann constant, T is the real-time temperature, and -△E is a constant;

[0063] from Figure 2 As can be seen in (b), each temperature point corresponds to a different fluorescence intensity ratio, but the fluorescence intensity versus temperature curves do not completely match, proving that its dependence on temperature is lower than that of the embodiment.

[0064] The absolute temperature sensitivity Sr is used to represent the rate of change of the FIR value with temperature, thereby verifying the feasibility of the material for temperature measurement:

[0065]

[0066] from Figure 2 (b) It can be seen that compared with Example 1, the material prepared in Comparative Example 2 is less sensitive to temperature.

[0067] Comparative Example 3

[0068] A method for preparing a negative thermal expansion material phosphor comprises:

[0069] (1) Add 0.02 mol Eu2O3 and 0.0375 mol Tb4O7 to a mixture of 1.905 mol Y2O3 and 6.0 mol MoO3, add ethanol and grind to obtain a mixture A.

[0070] (2) Mixed material A is placed in an alumina crucible and placed in a box furnace. In an air atmosphere, the temperature is raised to 850°C at a heating rate of 5°C / min and sintered for 6 hours. After cooling, Y2Mo3O 12 :Eu,Tb phosphor.

[0071] The negative thermal expansion material phosphor Y2Mo3O 12 : Application of Eu, Tb as temperature measurement:

[0072] The negative thermal expansion material phosphor Y2Mo3O 12 :Eu,Tb were heated at 20℃, 60℃, 100℃, 140℃, 180℃, 220℃, 260℃ and 300℃, and the fluorescence changes of the samples were not obvious. The fluorescence spectra tested by F7000 fluorescence spectrometer showed that the fluorescence intensity of green light (550nm) gradually decreased with increasing temperature, while the fluorescence intensity of red light (617nm) remained basically unchanged. The fitted fluorescence intensity ratio I 617nm / I 550nm With respect to the temperature, it is found that the curve of the fluorescence intensity ratio and the temperature cannot be completely consistent, and its sensitivity is low, and its dependence on temperature is weaker than that of the embodiment.

[0073] The above describes in detail the specific embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A method for preparing a negative thermal expansion material phosphor, characterized in that: include: (1) Eu2O3 and Tb4O7 were added to a mixture of Y2O3 and MoO3, respectively, and ethanol was added and ground to obtain mixed materials A and B; (2) Mixture A and mixture B are calcined separately to obtain Y2Mo3O 12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor; (3) Y2Mo3O 12 :Eu phosphor and Y2Mo3O 12 :Tb phosphor powder is mixed and ground in a molar ratio of 1:1 to obtain negative thermal expansion material phosphor powder; The molar ratio of Eu2O3, Y2O3 and MoO3 is 0.02:0.98:3.00; The molar ratio of Tb4O7, Y2O3 and MoO3 is 0.0375:0.9250:3.0000.

2. The method for preparing the negative thermal expansion material phosphor according to claim 1, wherein: The calcination temperature is 850° C., the calcination time is 6 hours, the heating rate is 5° C. / min, and the atmosphere is air.

3. The method for preparing the negative thermal expansion material phosphor according to claim 1, wherein: The grinding time is 10 min.

4. The negative thermal expansion material phosphor Y2Mo3O prepared by the preparation method of the negative thermal expansion material phosphor according to any one of claims 1 to 3 12 :Eu / Tb.

5. Use of the negative thermal expansion material phosphor according to claim 4 in a temperature sensor.

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