Erbium and ytterbium ion doped Al2O3-YAG composite ceramic sensing material and preparation method thereof

Abstract

The invention provides an erbium-ytterbium ion doped Al2O3-YAG composite ceramic sensing material and a preparation method thereof, and belongs to the technical field of crossing of functional ceramic materials and optical sensing technologies, the erbium-ytterbium ion doped Al2O3-YAG composite ceramic sensing material comprises a matrix phase and doped ions, the matrix phase is Al2O3-YAG (aluminum oxide-yttrium aluminum garnet) composite ceramic; wherein the mass ratio of Al2O3 is 30%-70%, and the mass ratio of YAG is 30%-70%; the doping ions are Er < 3 + > and Yb < 3 + >, and based on the total molar weight of the matrix phase, the doping concentration of Er < 3 + > is 0.5-3 mol%, and the doping concentration of Yb < 3 + > is 5-20 mol%; the sensing material realizes temperature sensing under the excitation of 980 nm laser and on the basis of the energy level emission conditions of 2H11 / 2 to 4I15 / 2 and 4S3 / 2 to 4I15 / 2 of Er < 3 + >. The Al2O3-YAG composite ceramic is used as an Er < 3 + > / Yb < 3 + > doped matrix for optical temperature measurement for the first time, and the high-temperature stability is superior to that of fluorescent powder and glass materials; the mechanical strength and the thermal shock resistance are obviously improved; elements are uniformly distributed, and the concentration quenching effect is avoided.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of functional ceramic materials and optical sensing technology, specifically referring to an erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material and its preparation method. Background Technology

[0002] High-precision temperature measurement is in high demand in fields such as industrial process control, aerospace, energy equipment, and biomedicine. Traditional contact temperature measurement methods, such as thermocouples, have significant limitations in high-temperature, highly corrosive, and electromagnetically interfered environments. Non-contact optical temperature sensing based on fluorescence intensity ratio (FIR) technology has become a research hotspot due to its advantages such as strong anti-interference ability, high spatial resolution, and fast response speed.

[0003] Currently used FIR materials include phosphors, fluorides, nanocrystals, and glass ceramics, but they generally suffer from poor high-temperature stability, luminous efficiency degradation, and insufficient mechanical strength. Rare earth ions (Er) 3+ / Yb 3+ Co-doped systems have unique thermally coupled energy levels ( 2 H 11 / 2 and 4 S 3 / 2 Al₂O₃-YAG eutectic composites are widely recognized as ideal FIR (First-In, Second-Out) temperature sensing materials due to their high melting point (>1500℃), good thermal stability, excellent mechanical strength, and strong chemical inertness. However, existing material systems exhibit phase transitions, elemental segregation, and luminescence quenching in oxidizing environments above 800℃. However, research on using Al₂O₃-YAG as an optical functional matrix for temperature sensing has not yet been systematically reported. Summary of the Invention

[0004] To overcome some of the problems mentioned in the background above, the present invention provides an erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material to at least partially solve the above problems.

[0005] According to the technical solution of the present invention, an erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material is provided, comprising a matrix phase and dopant ions;

[0006] The matrix phase is an Al2O3-YAG composite ceramic; wherein the mass percentage of Al2O3 is 30%~70% and the mass percentage of YAG is 30%~70%.

[0007] The doped ion is Er 3+ and Yb 3+ Based on the total molar amount of the matrix phase, Er 3+ The doping concentration is 0.5~3 mol%, Yb3+ The doping concentration is 5~20 mol%;

[0008] The sensing material, under 980 nm laser excitation, is based on Er 3+ of 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 Temperature sensing is achieved under the condition of energy level emission.

[0009] Preferably, the mass percentage of Al2O3 in the matrix phase is 50%~60%, and the mass percentage of YAG is 40%~50%.

[0010] Preferably, the Er 3+ The doping concentration is 1~2 mol%, Yb 3+ The doping concentration is 10~15 mol.

[0011] Preferably, the relative sensitivity of the material is not less than 1.5%·K in the temperature range of 300~800 K. -1 Temperature measurement resolution ≤ 0.1K.

[0012] On the other hand, the present invention also provides a method for preparing the erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material described above, comprising the following steps:

[0013] (1) Raw material pretreatment: α-Al2O3 powder, Y2O3 powder, Er2O3 powder and Yb2O3 powder are mixed in proportion, sintering aid is added and then placed in a ball mill, ball milled for 12~24h with ethanol as dispersant, dried and passed through a 200-mesh sieve;

[0014] (2) Molding: The mixed powder obtained in step (1) is dry-pressed under a pressure of 10~30 MPa, and then isostatically pressed under a pressure of 100~200 MPa to obtain a green body;

[0015] (3) Sintering: The green blank is placed in a vacuum sintering furnace and heated to 1600-1800℃ at a rate of 5-10℃ / min. It is held for 3-6 hours and then cooled to room temperature with the furnace to obtain the sensing material.

[0016] Preferably, the sintering aid in step (1) is tetraethyl orthosilicate or MgO, and the amount added is 0.1% to 0.5% of the total mass of the matrix phase.

[0017] Preferably, the ball milling speed in step (1) is 300~500 r / min and the ball-to-material ratio is (5~10):1.

[0018] Preferably, the vacuum degree in step (3) is ≤1×10 -3 Pa, cooling rate is 2~5℃ / min.

[0019] Furthermore, the present invention also provides an application of the erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material described above in non-contact high-temperature temperature measurement, the application scenarios of which include hot-end monitoring of aero-engines, temperature detection of semiconductor etching cavities, or temperature measurement of nuclear reactor environments.

[0020] Furthermore, the present invention also provides an optical temperature sensor, comprising the Er sensor described in claim 1. 3+ and Yb 3+ Co-doped Al2O3-YAG composite ceramic sensing material, 980nm laser excitation module and fluorescence signal acquisition module.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention is the first to use Al2O3-YAG composite ceramics as Er 3+ / Yb 3+ The doped matrix is ​​used for optical temperature measurement, and its high-temperature stability is superior to that of phosphors and glass materials; its mechanical strength and thermal shock resistance are significantly improved; and its elemental distribution is uniform, avoiding the concentration quenching effect.

[0023] The conventional solid-state sintering method of this invention is suitable for large-scale production and applicable to extreme environmental temperature monitoring in gas turbines, high-temperature reactors, spacecraft thermal protection systems, and other applications. Attached Figure Description

[0024] Figure 1 The XRD patterns are those of Examples 1-4 of this invention;

[0025] Figure 2 These are microstructure diagrams of embodiments 1-4 of the present invention;

[0026] Figure 3 Examples 1-4 of this invention illustrate the relationship between upconversion emission spectra and power.

[0027] Figure 4 This is the temperature sensitivity and sensitivity curve of Example 1 of the present invention;

[0028] Figure 5 This is the temperature sensitivity and sensitivity curve of Example 3 of the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection.

[0030] This invention provides an erbium-ytterbium ion-doped Al2O3-YAG composite ceramic material, comprising a matrix phase and dopant ions;

[0031] The matrix phase is an Al2O3-YAG composite ceramic; wherein the mass percentage of Al2O3 is 30%~70% and the mass percentage of YAG is 30%~70%.

[0032] The doped ion is Er 3+ and Yb 3+ Based on the total molar amount of the matrix phase, Er 3+ The doping concentration is 0.5~3 mol%, Yb 3+ The doping concentration is 5~20 mol%

[0033] The sensing material, under 980 nm laser excitation, is based on Er 3+ of 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 Temperature sensing is achieved under the condition of energy level emission.

[0034] In a further embodiment of this example, the mass percentage of Al2O3 in the matrix phase is 50%~60%, and the mass percentage of YAG is 40%~50%.

[0035] In a further embodiment of this example, the Er 3+ The doping concentration is 1~2 mol%, Yb 3+ The doping concentration is 10~15 mol.

[0036] In a further embodiment of this example, the relative sensitivity of the material is not less than 1.5%·K in the temperature range of 300~800 K. -1 Temperature measurement resolution ≤ 0.1K.

[0037] On the other hand, embodiments of the present invention also provide a method for preparing the erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material described above, comprising the following steps:

[0038] (1) Raw material pretreatment: α-Al2O3 powder, Y2O3 powder, Er2O3 powder and Yb2O3 powder are mixed in proportion, sintering aid is added and then placed in a ball mill, ball milled for 12~24h with ethanol as dispersant, dried and passed through a 200-mesh sieve;

[0039] (2) Molding: The mixed powder obtained in step (1) is dry-pressed under a pressure of 10~30 MPa, and then isostatically pressed under a pressure of 100~200 MPa to obtain a green body;

[0040] (3) Sintering: The green blank is placed in a vacuum sintering furnace and heated to 1600-1800℃ at a rate of 5-10℃ / min. It is held for 3-6 hours and then cooled to room temperature with the furnace to obtain the sensing material.

[0041] In a further embodiment of this example, the sintering aid in step (1) is tetraethyl orthosilicate or MgO, and the amount added is 0.1% to 0.5% of the total mass of the matrix phase.

[0042] In a further embodiment of this example, the ball milling speed in step (1) is 300~500 r / min and the ball-to-material ratio is (5~10):1.

[0043] In a further embodiment of this example, the vacuum degree in step (3) is ≤1×10 -3 Pa, cooling rate is 2~5℃ / min.

[0044] Furthermore, this embodiment of the invention also provides an application of the erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material described above in non-contact high-temperature temperature measurement. The application scenarios include hot-end monitoring of aero-engines, temperature detection of semiconductor etching cavities, or temperature measurement of nuclear reactor environments.

[0045] A further embodiment of the present invention also provides an optical temperature sensor, including the Er sensor described in claim 1. 3+ and Yb 3+ Co-doped Al2O3-YAG composite ceramic sensing material, 980nm laser excitation module and fluorescence signal acquisition module.

[0046] It should be noted that: (1) Raw material selection and proportioning design:

[0047] Formulas were designed using high-purity Al₂O₃ (99.99%), Y₂O₃ (99.99%), Er₂O₃ (99.99%), and Yb₂O₃ (99.99%) powders according to the following molar percentages: Er 3+ With a fixed doping concentration of 1 mol% for Yb 3+The doping concentration gradient is 2 mol%, 4 mol%, 5 mol%, and 8 mol%.

[0048] (2) Powder pretreatment and mixing:

[0049] The powder was ball-milled for 12 hours at 360 r / min using a rotary ball mill (ZrO2 grinding balls, ethanol medium) to ensure uniform mixing and particle size control.

[0050] (3) Drying and sieving process:

[0051] After the slurry is dried at 60°C for 24 hours, it is sieved three times through a 180-mesh sieve to obtain a molding powder with good flowability.

[0052] (4) Molding and densification:

[0053] After initial forming by uniaxial pressing (2MPa), the density of the billet is increased by cold isostatic pressing (200MPa).

[0054] (5) Segmented sintering system:

[0055] Pre-sintering at 1200℃ for 10 hours under an oxygen atmosphere removes organic impurities and achieves preliminary densification. Then, a high-temperature solid-state reaction at 1700℃ for 7 hours promotes grain boundary migration and complete densification.

[0056] (6) Post-processing:

[0057] Double-sided mirror polishing to a surface roughness Ra < 5 nm meets optical testing requirements.

[0058] Structural characterization and performance analysis:

[0059] XRD analysis showed that all samples were pure phases of Al2O3 (PDF#71-1128) and YAG (PDF#88-2048), with no impurity phases formed. (The last sentence appears to be incomplete and possibly refers to a different topic.) 3+ With increasing concentration, the diffraction peaks of the YAG phase (420) crystal plane shift towards smaller angles, indicating that Yb 3+ (0.86Å) successfully replaced Y 3+ (0.90 Å) causes lattice expansion. SEM microstructure shows that the Al2O3 phase (dark area) is embedded in the YAG phase (bright area) in an irregular shape, and the interface between the two phases is clear and tightly bonded. EDS surface scanning confirms that Er and Yb elements are uniformly distributed in the ceramic.

[0060] Optical performance study:

[0061] Under 980nm laser excitation, the sample exhibits typical upconversion luminescence characteristics: the 524nm emission peak corresponds to Er 3+ : 2 H 11 / 2 →4 I 15 / 2 The transition, the 561nm emission peak corresponds to Er 3+ : 4 S 3 / 2 → 4 I 15 / 2 The transition, with luminescence intensity showing a quadratic relationship to excitation power, confirms it as a two-photon upconversion process.

[0062] Temperature sensing characteristics:

[0063] Within the temperature range of 293–493K: 2 H 11 / 2 The energy level emission intensity increases with increasing temperature. 4 S 3 / 2 The energy level emission intensity decreases with increasing temperature, and the FIR values ​​(I524 / I561) conform to the Boltzmann distribution model.

[0064] FIR = Aexp( ) + B,

[0065] Where ΔE is the thermal coupling energy level difference (339–540 cm⁻¹). -1 ), where k is the Boltzmann constant. The absolute sensitivity (Sa) reaches 0.002 K at 493 K. -1 The relative sensitivity (Sr) reaches 0.009 K at 293 K. -1 .

[0066] Example 1

[0067] High-purity raw materials of Al2O3, Y2O3, Er2O3, and Yb2O3 were weighed according to 1.0 at% Er and 2.0 at% Yb, with a total weight of 10.0 g. After ball milling and mixing, the mixture was dried and sieved. It was then shaped into rods and sealed. The rods were cold isostatically pressed at 200 MPa for 2 min and pre-sintered at 1200 °C for 10 hours in an oxygen atmosphere to remove organic impurities and achieve preliminary densification. The mixture was then subjected to a high-temperature solid-state reaction at 1700 °C for 7 hours to promote grain boundary migration and complete densification. Finally, the mixture was slowly cooled to room temperature and the ceramic was removed.

[0068] Example 2

[0069] High-purity raw materials of Al2O3, Y2O3, Er2O3, and Yb2O3 were weighed according to 1.0 at% Er and 4.0 at% Yb, with a total weight of 10.0 g. After ball milling and mixing, the mixture was dried and sieved. It was then shaped into rods and sealed. It was cold isostatically pressed at 200 MPa for 2 min, pre-sintered at 1200 °C for 10 hours in an oxygen atmosphere to remove organic impurities and achieve preliminary densification, and then subjected to a high-temperature solid-state reaction at 1700 °C for 7 hours to promote grain boundary migration and complete densification. Finally, it was slowly cooled to room temperature and the ceramic was removed.

[0070] Example 3

[0071] High-purity raw materials of Al2O3, Y2O3, Er2O3, and Yb2O3 were weighed according to 1.0 at% Er and 5.0 at% Yb, with a total weight of 10.0 g. After ball milling and mixing, the mixture was dried and sieved. It was then shaped into rods and sealed. It was cold isostatically pressed at 200 MPa for 2 min, pre-sintered at 1200 °C for 10 hours in an oxygen atmosphere to remove organic impurities and achieve preliminary densification, and then subjected to a high-temperature solid-state reaction at 1700 °C for 7 hours to promote grain boundary migration and complete densification. Finally, it was slowly cooled to room temperature and the ceramic was removed.

[0072] Example 4

[0073] High-purity raw materials of Al2O3, Y2O3, Er2O3, and Yb2O3 were weighed according to 1.0 at% Er and 8.0 at% Yb, with a total weight of 10.0 g. After ball milling and mixing, the mixture was dried and sieved. It was then shaped into rods and sealed. It was cold isostatically pressed at 200 MPa for 2 min, pre-sintered at 1200 °C for 10 hours in an oxygen atmosphere to remove organic impurities and achieve preliminary densification, and then subjected to a high-temperature solid-state reaction at 1700 °C for 7 hours to promote grain boundary migration and complete densification. Finally, it was slowly cooled to room temperature and the ceramic was removed.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material, characterized in that, Including the matrix phase and dopant ions; The matrix phase is an Al2O3-YAG composite ceramic; wherein the mass percentage of Al2O3 is 30%~70% and the mass percentage of YAG is 30%~70%. The doped ion is Er 3+ and Yb 3+ Based on the total molar amount of the matrix phase, Er 3+ The doping concentration is 0.5~3 mol%, Yb 3+ The doping concentration is 5~20 mol% The sensing material, under 980 nm laser excitation, is based on Er 3+ of 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 Temperature sensing is achieved under the condition of energy level emission.

2. The erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material according to claim 1, characterized in that, The matrix phase contains 50% to 60% Al2O3 and 40% to 50% YAG by mass.

3. The erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material according to claim 1, characterized in that, The Er 3+ The doping concentration is 1~2 mol%, Yb 3+ The doping concentration is 10~15 mol.

4. The erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material according to claim 1, characterized in that, The relative sensitivity of the material is not less than 1.5%·K in the temperature range of 300~800 K. -1 Temperature measurement resolution ≤ 0.1K.

5. A method for preparing an erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Raw material pretreatment: α-Al2O3 powder, Y2O3 powder, Er2O3 powder and Yb2O3 powder are mixed in proportion, sintering aid is added and then placed in a ball mill, ball milled for 12~24h with ethanol as dispersant, dried and passed through a 200-mesh sieve; (2) Molding: The mixed powder obtained in step (1) is dry-pressed under a pressure of 10~30 MPa, and then isostatically pressed under a pressure of 100~200 MPa to obtain a green body; (3) Sintering: The green blank is placed in a vacuum sintering furnace and heated to 1600-1800℃ at a rate of 5-10℃ / min. It is held for 3-6 hours and then cooled to room temperature with the furnace to obtain the sensing material.

6. The method for preparing the erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material according to claim 5, characterized in that, The sintering aid in step (1) is tetraethyl orthosilicate or MgO, and the amount added is 0.1% to 0.5% of the total mass of the matrix phase.

7. The preparation method of the erbium-ytterbium ion-doped Al₂O₃-YAG composite ceramic sensing material according to claim 5, characterized in that, The ball milling speed in step (1) is 300~500 r / min, and the ball-to-material ratio is (5~10):

1.

8. The preparation method of the erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material according to claim 5, characterized in that, The vacuum degree in step (3) is ≤1×10 -3 Pa, cooling rate is 2~5℃ / min.

9. The application of the erbium-ytterbium ion-doped Al2O3-YAG composite ceramic sensing material according to any one of claims 1-4 in non-contact high-temperature temperature measurement, characterized in that: The application scenarios include hot-end monitoring of aero-engines, temperature detection of semiconductor etching cavities, or temperature measurement of nuclear reactor environments.

10. An optical temperature sensor, characterized in that: Including Er as described in claim 1 3+ and Yb 3+ Co-doped Al2O3-YAG composite ceramic sensing material, 980nm laser excitation module and fluorescence signal acquisition module.

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