A kind of Eu 3+ Doped perovskite structure fluorescent material and preparation method and application thereof

Abstract

The present invention discloses a Eu 3+ Doped CaZrO3 perovskite fluorescent material and its preparation method and application belong to the preparation and application field of pressure-sensitive fluorescent materials. The material is prepared by DC arc discharge method, and the chemical formula is: CaZrO3: xmol%Eu 3+ , where 0.5≤x≤2.4. Under 325nm excitation light, as the external pressure increases, CaZrO3: xmol%Eu 3+ The fluorescence emission peak is located in the long-wave range of 700nm ( 5 D0‑ 7 F4) and 615nm( 5 D0‑ 7 The intensity ratio of the two peaks (F2) increases exponentially. This behavior results in a material with an absolute pressure sensitivity of up to 75.8% / GPa and a relative pressure sensitivity of up to 226.9% / GPa. This material demonstrates great potential for application in fluorescence pressure measurement.

Description

Technical Field

[0001] The present invention relates to the field of fluorescent materials, and in particular to a high-sensitivity fluorescent material, a preparation method thereof, and an application thereof in the field of pressure calibration. Background Art

[0002] As a fundamental thermodynamic parameter, pressure has a significant influence on the structure and physicochemical properties of matter, and exhibits a wide range of application value in scientific research, industrial production, and daily life. Therefore, the accurate and precise measurement of pressure is of vital importance. Traditional pressure measurement methods require physical contact with the object being measured, making it difficult to accurately measure pressure in local microscopic areas and under certain special circumstances. Non-contact pressure measurement methods can indirectly measure pressure by sensing or detecting certain physical properties of the object being measured (such as electromagnetic fields, sound waves, light, etc.) without direct contact with the object being measured. In recent years, this non-contact pressure measurement method has received widespread attention from scientific researchers and has shown broad application prospects in many fields.

[0003] Fluorescence pressure detection, developed based on the luminescence properties of rare earth ions, is a commonly used non-contact optical pressure measurement technique. This technique measures pressure by monitoring the changes in a material's fluorescence parameters as a function of pressure. Typically, selected parameters include fluorescence peak position, fluorescence peak intensity, fluorescence peak full width at half maximum, fluorescence lifetime, and fluorescence peak-to-peak intensity ratio. The fluorescence peak-to-peak intensity ratio method is less dependent on the environment and is unaffected by factors such as fluorescence loss and laser source intensity fluctuations. It offers the advantages of self-referencing, accuracy, fast response, and reliability.

[0004] The optical material used for pressure gauges should have excellent mechanical structural stability and light sensitivity to meet the requirements of accurate and reliable pressure calibration over a wide pressure range. In addition, long-wave emission light has the characteristics of low transmission loss and strong penetration compared to short-wave emission light, which has advantages in realizing long-distance, non-contact pressure sensing applications in complex environments. At present, the optical pressure gauge materials used in practical applications are based on Al2O3:Cr 3+ (Ruby) and SrB4O7:Sm 2+ The red emission peak of the two pressure-standard materials has a relatively low pressure sensitivity (dλ / dP ~0.35 nm GPa). -1 ; ~ 0.25 nm GPa -1 ) and is easily affected by temperature. The pressure-standard materials based on fluorescence intensity ratio reported in the literature include Ca5(PO4)3F:Eu 2+ / Eu 3+ , SrB4O7:Eu 2+ / Sm 2+ and Li4SrCa(SiO4)2:Eu 2+However, their sensitivity to pressure is generally low. Currently, the research on pressure calibration using fluorescence intensity ratio is still in its infancy, and the selection of matrix and luminescence center needs to be further explored.

[0005] Based on this, this patent is dedicated to the preparation of a perovskite structure CaZrO3 with excellent mechanical stability as the matrix and a red-orange light emitting center Eu 3+ As a fluorescent material doped with Eu 3+ The fluorescence peak intensity ratio method achieves high-sensitivity pressure calibration and is expected to be used in the field of non-contact pressure measurement. Summary of the Invention

[0006] The present invention aims to solve the problems existing in the current pressure detection field and provides a method based on Eu 3+ A highly sensitive fluorescent material doped with a perovskite structure CaZrO3 and a preparation method thereof. The preparation method of the material is simple and easy to operate, and does not involve a complex chemical synthesis process.

[0007] The technical solution adopted by the present invention is: a Eu 3+ The doped perovskite structure fluorescent material is characterized in that the chemical formula of the material is: CaZrO3: xmol%Eu 3+ , where x is the molar percentage of doped trivalent europium ions, 0.5≤x≤2.4.

[0008] Preferably, the molar percentage x=0.5 or 1.

[0009] The present invention also provides a Eu 3+ The preparation method of the doped perovskite structure fluorescent material comprises the following steps: (1) weighing CaZrO3 and Eu2O3 powders of bulk perovskite structure at a molar ratio of 100:x, wherein 0.5≤x≤2.4; uniformly mixing the raw materials, pre-pressing them into thick sheets using a mold, and then placing them into a graphite crucible in a DC arc reaction device; (2) evacuating the reaction chamber and introducing inert gas argon as a protective gas; (3) the conditions required during the DC arc discharge process are: voltage range 20V to 24V, current 100A, and reaction time 2 to 3min; (4) waiting for the temperature of the graphite crucible to drop to room temperature, collecting the Eu2O3 therein; 3+ Doped CaZrO3 bulk material.

[0010] Preferably, the molar percentage x=0.5 or 1.

[0011] Another object of the present invention is to provide an application of the fluorescent material described in the above technical solution in the field of pressure calibration. 3+The 615nm and 700nm fluorescence peaks are detected, and the ambient pressure of the material is calibrated according to the intensity ratio of the two peaks.

[0012] Preferably, the maximum pressure range of the environment in which the fluorescent material is located is 0.36 to 12.12 GPa.

[0013] Under the action of external pressure, the fluorescence peak intensity of the fluorescent material of the present invention is greater than I 700 / I 615 It is significantly enhanced, and the absolute pressure sensitivity (75.8% / GPa) and relative sensitivity (226.9% / GPa) are extremely high, which is several to dozens of times higher than other optical pressure measurement materials based on the fluorescence emission peak intensity ratio, and is expected to be used in the field of pressure calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Shown is a schematic diagram of the material preparation device used in the present invention

[0015] Figure 2 The material CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ and X-ray diffraction spectrum of the reactant CaZrO3

[0016] Figure 3 The material CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ Fluorescence spectrum under 325nm laser excitation

[0017] Figure 4 The material CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ and X-ray diffraction spectrum of the reactant CaZrO3

[0018] Figure 5 The material CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ Fluorescence spectrum under 325nm laser excitation

[0019] Figure 6 The material CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ and X-ray diffraction spectrum of the reactant CaZrO3

[0020] Figure 7 The material CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ Fluorescence spectrum under 325nm laser excitation

[0021] Figure 8The material CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ High-pressure fluorescence spectrum under 325nm laser excitation

[0022] Figure 9 The material CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ The fluorescence intensity ratio (I 700 / I 615 )Data and fitted line

[0023] Figure 10 The material CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ In the range of 0.36~12.12GPa, the absolute (S a ) and relative pressure sensitivity (S r ) spectral lines

[0024] Figure 11 The material CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ High-pressure fluorescence spectrum under 325nm laser excitation

[0025] Figure 12 The material CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ In 10 -4 The fluorescence intensity ratio (I 700 / I 615 )Data and fitted line

[0026] Figure 13 The material CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ In 10 -4 Absolute (S a ) and relative pressure sensitivity (S r ) spectral lines

[0027] Figure 14 The material CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ High-pressure fluorescence spectrum under 325nm laser excitation

[0028] Figure 15 The material CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ In 10 -4 The fluorescence intensity ratio (I 700 / I 615)Data and fitted line

[0029] Figure 16 The material CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ In 10 -4 Absolute (S a ) and relative pressure sensitivity (S r ) spectral lines DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and examples. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] Figure 1 It is a structural schematic diagram of the material preparation device used in the present invention.

[0032] like Figure 1 As shown, the glass cover 1 in the reaction device is provided with a condensation wall 2, a metal tungsten cathode 3 and a graphite support anode 5 inside. The graphite support anode 5 contains the reaction raw materials 4 pre-pressed into thick sheets. The graphite support anode 5 is fixed above the copper base 6. During the experiment, the high-temperature plasma discharge between the metal tungsten cathode 3 and the graphite support anode 5 was controlled by adjusting the vertical position of the copper base 6. At the same time, the device was cooled in time by using the water inlet 9 and water outlet 10 in contact with the condensation wall 2 and the water inlet and water outlet on the copper base 6 in contact with the graphite support anode 5. Before and after the reaction, the reaction chamber needs to be repeatedly flushed through the air inlet 7 and the air outlet 8. Finally, the reaction products are collected in the graphite support anode 5.

[0033] Example 1

[0034] In this embodiment, a fluorescent material is prepared, and the preparation process is as follows:

[0035] Firstly, the bulk phase of the powder sample CaZrO3 and Eu2O3 was prepared according to the 3+ The molar ratio is 100:0.5, the mixture is fully ground and mixed, and then pre-pressed into a thick sheet with a diameter of 2.0 cm and a height of 1.6 cm as the reaction raw material 4, which is then placed in the graphite support anode 5 in the reaction chamber of the arc device. The metal tungsten cathode 3 is fixed directly above the reaction raw material thick sheet 4. Figure 1As shown, the metal tungsten cathode 3, the thick sheet of reaction material 4, and the graphite holder anode 5 are coaxial. The reaction chamber is evacuated and flushed with argon multiple times, finally filled with 10 kPa of argon as a shielding gas. The water circulation system is activated to flow cooling water to the condenser wall 2 and the copper base 6. The height of the copper base 6 is adjusted to reduce the distance between the metal tungsten cathode 3 and the thick sheet of reaction material 4. This allows high-temperature plasma discharge to occur between the metal tungsten cathode 3 and the graphite holder anode 5 through the thick sheet of reaction material 4, and the reaction begins. During the reaction, the interelectrode voltage is maintained at 20-24 V, the current at 100 A, and the reaction time is 2-3 minutes. After the reaction is completed, the reaction products are collected inside the graphite holder.

[0036] from Figure 2 The X-ray diffraction spectrum shown in the figure shows that CaZrO3:0.5mol%Eu 3+ It still maintains the same orthorhombic structure as the bulk CaZrO3. The diffraction spectrum contains no impurity peaks, indicating that the obtained sample is of high purity.

[0037] from Figure 3 From the fluorescence spectrum, it can be seen that fluorescence peaks appear at about 540nm, 590nm, 615nm, 655nm and 700nm, corresponding to Eu 3+ of 5 D1- 7 F 1,2 、 5 D0- 7 F1, 5 D0- 7 F2, 5 D0- 7 F3 and 5 D0- 7 F4 transition. Spectral test results show that Eu 3+ It has been successfully doped into the CaZrO3 matrix and exhibits characteristic long-wavelength red-orange light emission. The long-wavelength emission has strong penetrating power and is suitable for long-distance, non-contact pressure measurement.

[0038] Example 2

[0039] In this embodiment, a fluorescent material is prepared, and the preparation process is as follows:

[0040] Firstly, the bulk phase of the powder sample CaZrO3 and Eu2O3 was prepared according to the 3+ The molar ratio is 100:1.0, the mixture is fully ground and mixed, and then pre-pressed into a thick sheet with a diameter of 2.0 cm and a height of 1.6 cm as the reaction raw material 4, which is then placed in the graphite support anode 5 in the reaction chamber of the arc device. The metal tungsten cathode 3 is fixed directly above the reaction raw material thick sheet 4. Figure 1As shown, the metal tungsten cathode 3, the thick sheet of reaction material 4, and the graphite holder anode 5 are coaxial. The reaction chamber is evacuated and flushed with argon multiple times, finally filled with 10 kPa of argon as a shielding gas. The water circulation system is activated to flow cooling water to the condenser wall 2 and the copper base 6. The height of the copper base 6 is adjusted to reduce the distance between the metal tungsten cathode 3 and the thick sheet of reaction material 4. This allows high-temperature plasma discharge to occur between the metal tungsten cathode 3 and the graphite holder anode 5 through the thick sheet of reaction material 4, and the reaction begins. During the reaction, the interelectrode voltage is maintained at 20-24 V, the current at 100 A, and the reaction time is 2-3 minutes. After the reaction is completed, the reaction products are collected inside the graphite holder.

[0041] from Figure 4 The X-ray diffraction spectrum shown in the figure shows that CaZrO3:1.0mol%Eu 3+ It still maintains the same orthorhombic structure as the bulk CaZrO3. The diffraction spectrum contains no impurity peaks, indicating that the obtained sample is of high purity.

[0042] from Figure 5 From the fluorescence spectrum, it can be seen that fluorescence peaks appear at about 540nm, 590nm, 615nm, 655nm and 700nm, corresponding to Eu 3+ of 5 D1- 7 F 1,2 、 5 D0- 7 F1, 5 D0- 7 F2, 5 D0- 7 F3 and 5 D0- 7 F4 transition. Spectral test results show that Eu 3+ It has been successfully doped into the CaZrO3 matrix and exhibits characteristic long-wavelength red-orange light emission. The long-wavelength emission has strong penetrating power and is suitable for long-distance, non-contact pressure measurement.

[0043] Example 3

[0044] In this embodiment, a fluorescent material is prepared, and the preparation process is as follows:

[0045] Firstly, the bulk phase of the powder sample CaZrO3 and Eu2O3 was prepared according to the 3+ The molar ratio is 100:2.4, the mixture is fully ground and mixed, and then pre-pressed into a thick sheet with a diameter of 2.0 cm and a height of 1.6 cm as the reaction raw material 4, which is then placed in the graphite support anode 5 in the reaction chamber of the arc device. The metal tungsten cathode 3 is fixed directly above the reaction raw material thick sheet 4. Figure 1As shown, the metal tungsten cathode 3, the thick sheet of reaction material 4, and the graphite holder anode 5 are coaxial. The reaction chamber is evacuated and flushed with argon multiple times, finally filled with 10 kPa of argon as a shielding gas. The water circulation system is activated to flow cooling water to the condenser wall 2 and the copper base 6. The height of the copper base 6 is adjusted to reduce the distance between the metal tungsten cathode 3 and the thick sheet of reaction material 4. This allows high-temperature plasma discharge to occur between the metal tungsten cathode 3 and the graphite holder anode 5 through the thick sheet of reaction material 4, and the reaction begins. During the reaction, the interelectrode voltage is maintained at 20-24 V, the current at 100 A, and the reaction time is 2-3 minutes. After the reaction is completed, the reaction products are collected inside the graphite holder.

[0046] from Figure 6 The X-ray diffraction spectrum shown in the figure shows that CaZrO3:2.4mol%Eu 3+ It still maintains the same orthorhombic structure as the bulk CaZrO3. The diffraction spectrum contains no impurity peaks, indicating that the obtained sample is of high purity.

[0047] from Figure 7 From the fluorescence spectrum, it can be seen that fluorescence peaks appear at about 540nm, 590nm, 615nm, 655nm and 700nm, corresponding to Eu 3+ of 5 D1- 7 F 1,2 、 5 D0- 7 F1, 5 D0- 7 F2, 5 D0- 7 F3 and 5 D0- 7 F4 transition. Spectral test results show that Eu 3+ It has been successfully doped into the CaZrO3 matrix and exhibits characteristic long-wavelength red-orange light emission. The long-wavelength emission has strong penetrating power and is suitable for long-distance, non-contact pressure measurement.

[0048] Figure 8 The CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ High-pressure fluorescence spectrum of the material. As can be seen from the figure, the fluorescence peak at about 700nm increases significantly with increasing pressure, while other fluorescence peaks gradually weaken with increasing pressure.

[0049] Figure 9 The CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ The fluorescence intensity ratio of the material in the range of 0.36~12.12GPa (I 700 / I 615) changes with pressure, the ratio satisfies the following fitting equation:

[0050] R=I 700 / I 615 =c1exp(P / c2)+c3, where c1, c2 and c3 are constants, and P is the ambient pressure.

[0051] Figure 10 The CaZrO3:0.5mol%Eu prepared in Example 1 is shown. 3+ A plot of the material's pressure sensitivity over the range of 0.36 to 12.12 GPa. The absolute pressure sensitivity increases with increasing pressure. At 12.12 GPa, the maximum absolute sensitivity is 75.8% / GPa; at 0.36 GPa, the relative sensitivity reaches a maximum of 226.9% / GPa.

[0052] Figure 11 The CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ High-pressure fluorescence spectrum of the material. As can be seen from the figure, the fluorescence peak at about 700nm increases significantly with increasing pressure, while other fluorescence peaks gradually weaken with increasing pressure.

[0053] Figure 12 The CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ Materials in 10 -4 The fluorescence intensity ratio (I 700 / I 615 ) changes with pressure, the ratio satisfies the following fitting equation:

[0054] R=I 700 / I 615 =c1exp(P / c2)+c3, where c1, c2 and c3 are constants, and P is the ambient pressure.

[0055] Figure 13 The CaZrO3:1.0mol%Eu prepared in Example 2 is shown. 3+ Materials in 10 -4 Pressure sensitivity diagram in the range of 10~7.23GPa. As the pressure increases, the absolute pressure sensitivity value increases continuously. At 7.23GPa, the maximum absolute sensitivity is 75.8% / GPa; at 10 -4 GPa, the relative sensitivity takes the maximum value of 123.3% / GPa.

[0056] Figure 14 The CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+High-pressure fluorescence spectrum of the material. As can be seen from the figure, the fluorescence peak at about 700nm increases significantly with increasing pressure, while other fluorescence peaks gradually weaken with increasing pressure.

[0057] Figure 15 The CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ Materials in 10 -4 The fluorescence intensity ratio (I 700 / I 615 ) changes with pressure, the ratio satisfies the following fitting equation:

[0058] R=I 700 / I 615 =c1exp(P / c2)+c3, where c1, c2 and c3 are constants, and P is the ambient pressure.

[0059] Figure 16 The CaZrO3:2.4mol%Eu prepared in Example 3 is shown. 3+ Materials in 10 -4 Pressure sensitivity diagram in the range of ~7.05GPa. As the pressure increases, the absolute pressure sensitivity value increases continuously. At 7.05GPa, the maximum absolute sensitivity is 44.4% / GPa; at 10 -4 GPa, the relative sensitivity takes the maximum value of 52.9% / GPa.

[0060] The present invention uses the emission peak intensity ratio pressure measurement method to obtain CaZrO3:xmol%Eu 3+ The material's absolute pressure sensitivity can reach up to 75.8% / GPa, and its relative pressure sensitivity can reach up to 226.9% / GPa. As shown in Table 1, the material's pressure sensitivity is much higher than that of other known optical pressure measurement materials based on fluorescence emission peak intensity ratios.

[0061] Table 1 Comparison of pressure sensitivity of pressure standard materials

[0062] Pressure marking materials <![CDATA[S a-max (GPa -1 )]]> <![CDATA[S r-max (GPa -1 )]]> <![CDATA[Pressure range (GPa -1 )]]> <![CDATA[Ca5(PO4)3F:Eu 2+ / Eu 3+ ]]> 4.73% 24.98% <![CDATA[10 -4 ~11.92]]> <![CDATA[SrB4O7: Eu 2+ / Sm 2+ ]]> 35% 13% <![CDATA[10 -4 ~40]]> <![CDATA[Li4SrCa(SiO4)2:Eu 2+ ]]> 29.9% 9.9 % <![CDATA[10 -4 ~15.69]]> <![CDATA[NaYF4:Er 3+ @NaYF4]]> — 19.59% <![CDATA[10 -4 ~7.14]]> <![CDATA[CaZrO3:0.5%Eu 3+ ]]> 75.8% 226.9% 0.36~12.12 <![CDATA[CaZrO3:1.0%Eu 3+ ]]> 75.8% 123.3% <![CDATA[10 -4 ~7.23]]> <![CDATA[CaZrO3:2.4%Eu 3+ ]]> 44.4% 52.9% <![CDATA[10 -4 ~7.05]]>

[0063] The above description is merely a specific embodiment of the present invention, which is used to illustrate the technical solution of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution of the invention may be modified or replaced by equivalents without departing from the scope of the technical solution of the present invention, and all of these modifications or equivalents should be included in the scope of the claims of the present invention.

Claims

1. A kind of Eu 3+ The application of doped perovskite structured fluorescent materials in the field of environmental pressure calibration is characterized by: The material has an orthorhombic structure and a general chemical formula of: CaZrO3: xmol%Eu 3+ , where x is the molar percentage of doped trivalent europium ions, 0.5≤x≤2.

4.

2. Eu according to claim 1 3+ The application of doped perovskite structured fluorescent materials in the field of environmental pressure calibration is characterized by: The molar percentage x=0.5 or 1.

3. Eu according to claim 1 or 2 3+ The application of doped perovskite structured fluorescent materials in the field of environmental pressure calibration is characterized by: The preparation method of the material comprises the following steps: (1) CaZrO3 and Eu2O3 powders of bulk perovskite structure were weighed at a molar ratio of 100:x; the raw materials were uniformly mixed and pre-pressed into thick sheets using a mold, and then placed into a graphite crucible in a DC arc reactor; (2) Evacuate the reaction chamber and introduce inert argon as a protective gas; (3) The conditions required during DC arc discharge are: voltage range 20V~24V, current 100A, and reaction time 2~3min; (4) When the temperature of the graphite crucible drops to room temperature, collect the Eu 3+ Doped CaZrO3 bulk material.

4. The use of the fluorescent material according to claim 1 in the field of environmental pressure calibration, characterized in that: The application environment pressure range is 0.36 to 12.12 GPa.

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