Photochromic ceramic material and its use in temperature sensing

Abstract

The application discloses a photochromic ceramic material and application thereof in temperature sensing. 1.9‑x NaNb5O 15 :0.10Yb,xEr, wherein x=0.01-0.15. The material has the characteristics that the photochromic effect promotes the up-conversion temperature sensing performance, that is, the photochromic effect of the material can be used to control the luminescence intensity of each energy level, thereby promoting the temperature sensing performance of the material, and the photochromic effect of the material can promote the absolute sensitivity of the temperature sensing of the thermal coupling energy level by 27%, and the relative sensitivity by 19.4%.

Description

Technical Field

[0001] This invention belongs to the field of solid-state luminescent materials, specifically relating to a ceramic material that uses photochromism to induce a change in fluorescence intensity ratio, thereby improving temperature sensing performance, and its application in temperature sensing. Background Technology

[0002] In recent years, with the surge in demand for thermal measurement in diverse fields such as biomedical diagnostics, industrial manufacturing, and extreme environments (e.g., corrosive media, strong magnetic fields, and high radiation conditions), non-invasive thermal measurement technologies have made significant progress. Against this backdrop, optical temperature sensing technologies based on key optical parameters (such as luminescence intensity, fluorescence intensity ratio, spectral bandwidth, and emission lifetime) have received widespread research attention. Of particular note is the widespread adoption of fluorescence intensity ratio (FIR) as the dominant optical parameter for temperature detection. This preference stems from its inherent resistance to spectral attenuation and excitation power fluctuations, thus ensuring enhanced stability and reliability in the thermal measurement process. While the application of rare-earth ion-based fluorescence intensity ratio in temperature sensing technology has made some progress over the past decade, its relatively low absolute and relative sensitivity falls far short of practical application requirements. Therefore, it is necessary to develop a new method to improve temperature sensing performance to meet the practical temperature measurement needs in various scenarios and complex environments. Summary of the Invention

[0003] The purpose of this invention is to provide a ceramic material with stable structure, excellent photochromic properties and improved temperature sensing performance. The photochromic effect of this material can improve the absolute sensitivity of temperature sensing of thermally coupled energy levels by 27% and the relative sensitivity by 19.4%.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A photochromic ceramic material with the general chemical formula Sr 1.9-x NaNb5O 15 :0.10Yb,xEr, where x=0.01~0.15.

[0005] Specifically, the chemical formula of the photochromic ceramic material is Sr 1.89 NaNb5O 15 0.10Yb, 0.01Er, Sr 1.875 NaNb5O 15 0.10Yb, 0.025Er, Sr 1.85 NaNb5O 15 0.10Yb, 0.05Er, Sr 1.825 NaNb5O 15 0.10Yb, 0.075Er, Sr 1.8NaNb5O 15 0.10Yb, 0.10Er, Sr 1.75 NaNb5O 15 :0.10Yb,0.15Er.

[0006] Furthermore, the photochromic ceramic material is prepared by mixing raw materials SrCO3, Na2CO3, Nb2O5, Yb2O3 and Er2O3 according to the elemental stoichiometric ratio, and then pre-sintering and sintering.

[0007] Furthermore, the pre-sintering temperature is 950~1050℃, and the time is 4~6h.

[0008] Furthermore, the sintering temperature is 1300~1380℃, and the time is 2~4h.

[0009] The photochromic ceramic material can be used for temperature sensing.

[0010] The beneficial effects of this application are as follows: This invention provides a ceramic material that can enhance temperature sensing performance using a photochromic effect. With increasing temperature, energy transfer occurs between the defect state energy level introduced by the photochromic effect and the upconversion luminescent energy level, thereby increasing the fluorescence intensity ratio between different luminescent energy levels in the thermally coupled energy level, thus improving the sensitivity and signal response of temperature sensing. Therefore, this material exhibits the characteristic of significantly improving temperature sensing performance through a photochromic effect, increasing the absolute sensitivity of the thermally coupled energy level by 27% and the relative sensitivity by 19.2%. Furthermore, its fabrication process is simple and inexpensive, making it a promising candidate for practical applications in the field of temperature sensing. Attached Figure Description

[0011] Figure 1 The X-ray diffraction pattern of the photochromic ceramic material prepared in Example 1 is shown.

[0012] Figure 2 The image shows a scanning electron microscope (SEM) image of the photochromic ceramic material prepared in Example 2.

[0013] Figure 3 The ultraviolet diffuse reflectance spectra of the photochromic ceramic material prepared in Example 1 before and after 30 seconds of irradiation by a 365nm light source are shown, where (a) x=0.01, (b) x=0.025, (c) x=0.05, (d) x=0.075, (e) x=0.10, and (f) x=0.15.

[0014] Figure 4The upconversion emission spectra of the photochromic ceramic material prepared in Example 1 are shown in the temperature range of 293-683K and under excitation by a 980nm light source, where (a) x=0.01, (b) x=0.025, (c) x=0.05, (d) x=0.075, (e) x=0.10, and (f) x=0.15.

[0015] Figure 5 The upconversion emission spectrum of the photochromic ceramic material prepared in Example 1 after photochromism in the temperature range of 293-683K and excitation at 980nm is shown in (a) x=0.01, (b) x=0.025, (c) x=0.05, (d) x=0.075, (e) x=0.10, and (f) x=0.15.

[0016] Figure 6 The image shows a comparison of the normalized luminescence intensity of the photochromic ceramic material prepared in Example 1 before and after photochromism within a temperature range of 293-683K.

[0017] Figure 7 The fluorescence intensity ratio curves of the photochromic ceramic material prepared in Example 1 before and after photochromism are fitted at the thermally coupled energy level, where (a) x=0.01, (b) x=0.025, (c) x=0.05, (d) x=0.075, (e) x=0.10, and (f) x=0.15.

[0018] Figure 8 The absolute sensitivity curves of the photochromic ceramic material prepared in Example 1 before and after photochromism are fitted to the thermal coupling energy level, where (a) x=0.01, (b) x=0.025, (c) x=0.05, (d) x=0.075, (e) x=0.10, and (f) x=0.15.

[0019] Figure 9 The relative sensitivity curves of the photochromic ceramic material prepared in Example 1 before and after photochromism are fitted to the thermal coupling energy level, where (a) x=0.01, (b) x=0.025, (c) x=0.05, (d) x=0.075, (e) x=0.10, and (f) x=0.15. Detailed Implementation

[0020] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0021] Example 1: Preparation of Photochromic Ceramic Materials Analytical-pure SrCO3, Nb2O5, Na2CO3, Yb2O3, and Er2O3 powders were precisely weighed according to the required elemental molar ratio. The weighed powders were then placed in an agate mortar, and anhydrous ethanol was added to grind them until uniformly mixed. The resulting refined particles were then placed in an alumina crucible and placed in a muffle furnace, heated to 1000℃, and held at that temperature for 4 hours for pre-sintering. The powders were then placed back in the agate mortar, ground with anhydrous ethanol to refine the powders, and finally sintered in a muffle furnace at 1360℃ for 2 hours to synthesize Sr. 1.9-x NaNb5O 15 :0.10Yb,xEr (x=0.01, 0.025, 0.05, 0.075, 0.10, 0.15) ceramic materials, the sintered ceramic materials are further ground into powder. Example 2

[0022] Accurately weigh 2.1849 g SrCO3, 5.3162 g Nb2O5, 0.4240 g Na2CO3, 0.01576 g Yb2O3, and 0.0765 g Er2O3. Add anhydrous ethanol to an agate mortar and grind until uniformly mixed. Then, place the resulting refined particles in an alumina crucible and place it in a muffle furnace. Heat to 1000℃ and hold for 4 hours for pre-sintering. Next, place the powder in an agate mortar, add anhydrous ethanol, grind to refine the powder, and then sinter in a muffle furnace at 1360℃ for 2 hours to synthesize SrCO3. 1.85 NaNb5O 15 :0.10Yb,0.05Er ceramic materials, the sintered ceramic materials are further ground into powder.

[0023] Figure 1 This is the X-ray diffraction pattern of the photochromic ceramic material prepared in Example 1. The data in the figure show that the obtained photochromic ceramic material is similar to Sr... 1.9 NaNb5O 15 The PDF card is consistent with the original, proving that it is a pure phase and that no second phase was generated.

[0024] Figure 2 This is a scanning electron microscope (SEM) image of the photochromic ceramic material prepared in Example 2. The image shows that the sintered particles are uniform and exhibit good ceramic-like properties.

[0025] Figure 3The image shows the ultraviolet diffuse reflectance spectra of the photochromic ceramic material prepared in Example 1 before and after 30 seconds of irradiation with a 365 nm light source. As can be seen from the image, after irradiation with a 365 nm light source, all different ceramic materials exhibit strong absorption in the visible light region, with photochromic degrees of 42.43% (x=0.01), 38.89% (x=0.025), 38.08% (x=0.05), 38.62% (x=0.075), 39.58% (x=0.10), and 30.65% (x=0.15), respectively.

[0026] Figure 4 The image shows the upconversion emission spectrum of the photochromic ceramic material prepared in Example 1 under excitation at 980 nm within a temperature range of 293-683 K. As can be seen from the figure, with increasing temperature, the upconversion emission intensity of the material first increases and then decreases around 530 nm, while around 550 nm and 670 nm, the upconversion emission intensity continuously decreases with increasing temperature.

[0027] Figure 5 The image shows the upconversion emission spectrum of the photochromic ceramic prepared in Example 1 after being irradiated with 365 nm for 30 s in the temperature range of 293-683 K to induce photochromism, followed by excitation at 980 nm. As can be seen from the figure, with increasing temperature, the upconversion emission intensity of the material first increases and then decreases near 530 nm, and also exhibits the same trend near 550 nm and 670 nm.

[0028] The photochromic ceramic material Sr prepared in Example 2 1.85 NaNb5O 15 Taking 0.10Yb and 0.05Er as an example, Figure 4 , 5 The displayed upconversion luminescence intensity was normalized to obtain Sr. 1.85 NaNb5O 15 Normalized luminescence intensities of 0.10Yb and 0.05Er at different temperatures are shown in the following figures. Figure 6 .Depend on Figure 6 It can be observed that there is a significant difference in the normalized upconversion luminescence intensity before and after irradiation.

[0029] exist Figure 4 , 5 Based on the data, the fluorescence intensity ratio (FIR) of the thermally coupled energy level fitted by the upconversion luminescence intensity is extracted (the formula for calculating the fluorescence intensity ratio FIR is: Where I1 and I2 represent the luminescence intensities of the two thermally coupled energy levels, g1 and g2 are the degeneracy of the two energy levels, ω1 and ω2 are the photon angular frequencies of the energy level transitions, A1 and A2 are the spontaneous emissivity of the two energy levels transitioning to the same lower energy level, K is the Boltzmann constant, T is the absolute temperature, and ΔE is the energy level spacing. Figure 7 .Depend on Figure 7 It can be observed that after the photochromic reaction, the fitted ΔE is significantly improved, and the fluorescence intensity ratio after the photochromic reaction is improved to a certain extent.

[0030] Based on the obtained fluorescence intensity ratio, the absolute and relative sensitivities of each photochromic ceramic material before and after photochromism were further fitted to obtain... Figure 8 , 9 Absolute sensitivity (S) a ) and relative sensitivity (S r The fitting formulas for ) are as follows:

[0031] Where FIR is the fluorescence intensity ratio, T is the absolute temperature, K is the Boltzmann constant, ΔE is the energy level spacing, and B is a constant.

[0032] Depend on Figure 8 , 9 It can be observed that after the photochromic reaction, both the absolute and relative sensitivity performances of the fitted data are improved to a certain extent, especially for the Sr sample. 1.85 NaNb5O 15 The photochromic effect of 0.10Yb and 0.05Er can improve the absolute sensitivity of temperature sensing of thermally coupled energy levels by 27% and the relative sensitivity performance by 19.4%.

[0033] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A photochromic ceramic material, characterized in that, The general chemical formula of the photochromic ceramic material is Sr 1.9-x NaNb5O 15 :0.10Yb,xEr, where x=0.01~0.

15.

2. The photochromic ceramic material according to claim 1, characterized in that, The chemical formula of the photochromic ceramic material is Sr. 1.89 NaNb5O 15 0.10Yb, 0.01Er, Sr 1.875 NaNb5O 15 0.10Yb, 0.025Er, Sr 1.85 NaNb5O 15 0.10Yb, 0.05Er, Sr 1.825 NaNb5O 15 0.10Yb, 0.075Er, Sr 1.8 NaNb5O 15 0.10Yb, 0.10Er, Sr 1.75 NaNb5O 15 :0.10Yb,0.15Er.

3. The photochromic ceramic material according to claim 1 or 2, characterized in that, It is prepared by mixing raw materials SrCO3, Na2CO3, Nb2O5, Yb2O3 and Er2O3 according to the element stoichiometric ratio, and then pre-sintering and sintering.

4. The photochromic ceramic material according to claim 3, characterized in that, The pre-sintering temperature is 950~1050℃, and the time is 4~6h.

5. The photochromic ceramic material according to claim 3, characterized in that, The sintering temperature is 1300~1380℃, and the time is 2~4h.

6. An application of the photochromic ceramic material as described in claim 1 in temperature sensing.

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