Rare earth high-temperature thermistor suitable for extreme temperature measurement and control and preparation method thereof

Abstract

The invention relates to a rare earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control, which is characterized in that high-entropy rare earth tantalate is used as a base material, niobium ions and TM ions are doped at a tantalum ion site at a B site, RE is five of rare earth elements of Tb, Dy, Ho, Er, Tm, Yb or Lu, TM is a transition metal element of V, W or Hf, and TM is a transition metal element of Tb, Dy, Ho, Er, Tm, Yb or Lu. The preparation method comprises the following steps: mixing five of raw materials including terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide and lutetium oxide with tantalum pentoxide and niobium pentoxide; the preparation method comprises the following steps of: mixing and grinding the raw materials and transition metal oxide vanadium pentoxide, tungsten trioxide or hafnium oxide, presintering, carrying out cold isostatic pressing, sintering at high temperature, and coating and burning an electrode to obtain a material with the constant B value of 14631-17732 K, the resistivity of 3.42 * 10 < 6 >-7.70 * 10 < 7 > omega.cm and ln (rho) at the temperature of 500 DEG C, the linear determination coefficient R2 of 1000 / T of 996.32-99.72 per mill, the aging coefficient of less than 5% after aging at the temperature of 1500 DEG C, stable resistance performance, and the like. The rare earth oxide high-temperature thermosensitive resistor has excellent negative temperature coefficient thermosensitive characteristics in a wide temperature range of 300-1500 DEG C. The invention further discloses a preparation method of the rare earth oxide high-temperature thermosensitive resistor.

Description

Technical Field

[0001] This invention relates to a rare earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control, and its preparation method. Background Technology

[0002] With the development of aero-engines, higher bypass ratios, thrust-to-weight ratios, and turbine inlet temperatures have led to a continuous rise in engine hot-end temperatures. The combustion chamber temperature of civilian turbofan engines has already reached over 1400℃, and is expected to potentially reach 1500℃. Precise temperature measurement and control is a core technology throughout the entire lifecycle of aero-engines, and its importance is reflected in the following two aspects: ① Safety assurance: Precise temperature field detection enables early warning of high-temperature hazards, and temperature field control enables hazard mitigation. ② Efficiency improvement: Rapid temperature measurement and control allows for precise adjustment of the engine temperature relative to the fuel mixture and intake air volume, achieving high fuel efficiency over extended periods. Therefore, precise temperature measurement in extreme high-temperature environments is crucial for achieving safe and green aviation.

[0003] Advanced high-temperature sensors should possess characteristics such as low cost, small size, fast response, and high reliability. Among these, reliability presupposes a stable resistance-temperature relationship at high temperatures and a low aging coefficient. Negative temperature coefficient (NTC) thermistors largely meet these requirements; however, their unstable resistance-temperature relationship at high temperatures and high aging coefficient limit their application in temperature measurement and control. Therefore, to ensure that thermistors can meet the requirements of high-temperature temperature measurement and control in aero-engines, there is an urgent need to develop a thermistor ceramic that exhibits a stable resistance-temperature relationship and a low aging coefficient at high temperatures.

[0004] Rare earth tantalates with the chemical formula RETaO4 exist in two crystal structures. RETaO4 ceramics (where RE = Tb-Er) have a monoclinic structure with an ferroelastic phase transition. m -phase), belonging to C2 / c Space group. RETaO4 (where RE = Tm-Lu) ceramics have a monoclinic structure without iron elastic phase transition. m (-phase), belonging to P2 / c Space group. Due to their high melting point and high-temperature semiconductivity, these rare-earth tantalates are promising candidates for novel high-temperature thermistor ceramics. However, their application in temperature measurement is limited by defects such as unstable temperature resistance at high temperatures and high aging coefficients. The average ionic radius of the A-site cation determines the monoclinic structure of the material ( m -phase or mThe '-phase' cannot bring about a leap in material performance. The cation at the B site is the main factor determining its structure (monoclinic single phase or precipitation of other phases), and also affects the material's conductivity and structural stability. By adding niobium ions and transition metal elements (one of V, W, or Hf) to the B site, not only is the configuration entropy further increased to improve the high-temperature stability of the structure, but also a low aging coefficient and a stable resistance-temperature relationship are achieved. Summary of the Invention

[0005] The purpose of this invention is to provide a rare-earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control, and its preparation method. The method uses five rare-earth oxides selected from terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, and lutetium trioxide, mixed with tantalum pentoxide, niobium pentoxide, and transition metal oxides vanadium pentoxide, tungsten trioxide, or hafnium dioxide. The mixture is then ground, pre-sintered, cold isostatically pressed, sintered at high temperature, and coated with electrodes. This yields a material with an applicable temperature range of 300-1500℃, a material constant B value ranging from 14631 to 17732 K, and a resistivity of 3.25 × 10⁻⁶ K at 500℃. 6 – 7.52×10 7 Ω.cm, ln( r ) and 1000 / T linear coefficients of determination R 2 The thermistors have an aging coefficient of 991.72-999.75‰ and an aging coefficient of less than 5% after aging at 1500℃.

[0006] This resistor exhibits stable performance and good consistency, and possesses excellent negative temperature coefficient characteristics over a wide temperature range of 300-1500℃, making it suitable for manufacturing high-temperature thermistors.

[0007] This invention discloses a rare-earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control. This material is based on high-entropy rare-earth tantalate, with niobium and TM ions incorporated at the B-site tantalum ion sites. RE represents five rare-earth elements: Tb, Dy, Ho, Er, Tm, Yb, or Lu; TM represents transition metal elements: V, W, or Hf. The raw material rare-earth oxides are five selected from terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, and lutetium trioxide, respectively, combined with tantalum pentoxide, niobium pentoxide, and the TM transition metal oxides vanadium pentoxide, tungsten trioxide, or hafnium dioxide. The specific operation is carried out according to the following steps: a. Weigh out the rare earth elements in a molar ratio of RE: Ta: Nb = 2:1:1 or RE: Ta: Nb: TM = 3:1:1:1, where RE is five rare earth elements in equimolar amounts of Tb, Dy, Ho, Er, Tm, Yb or Lu, and TM is transition metal elements V, W or Hf. Mix five rare earth oxides (terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide or lutetium trioxide) with tantalum pentoxide and niobium pentoxide, and transition metal oxides (vanadium pentoxide, tungsten trioxide or hafnium dioxide) in an agate mortar, grind for 7-9 h, then calcine at 1300-1350℃ for 3-5 h, and grind again for 6-8 h to obtain a dispersed pre-calcined powder. b. The pre-calcined powder obtained in step a is processed at a concentration of 15-25 kg / cm³. 2 The pressure is used to press the block into a block for 3-5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250-350 MPa for 4-6 minutes. Finally, it is sintered at a temperature of 1500-1550℃ for 10-14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400-1500℃ for 25 hours to obtain a material with a suitable temperature range of 300-1500℃ and a material constant B. The value ranges from 14631 to 17732 K, and the resistivity is 3.25 × 10⁻⁶ K at a temperature of 500 °C. 6 – 7.52×10 7 Ω.cm, ln( r ) and 1000 / T linear coefficients of determination R 2 The thermistors have an aging coefficient of 991.72-999.75‰ and an aging coefficient of less than 5% after aging at 1500℃.

[0008] A method for preparing a rare-earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control, comprising the following steps: a. Weigh out the rare earth elements in a molar ratio of RE: Ta: Nb = 2:1:1 or RE: Ta: Nb: TM = 3:1:1:1, where RE is five rare earth elements in equimolar amounts of Tb, Dy, Ho, Er, Tm, Yb or Lu, and TM is transition metal elements V, W or Hf. Mix five rare earth oxides (terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide or lutetium trioxide) with tantalum pentoxide and niobium pentoxide, and transition metal oxides (vanadium pentoxide, tungsten trioxide or hafnium dioxide) in an agate mortar, grind for 7-9 h, then calcine at 1300-1350℃ for 3-5 h, and grind again for 6-8 h to obtain a dispersed pre-calcined powder. b. The pre-calcined powder obtained in step a is processed at a concentration of 15-25 kg / cm³. 2 The pressure is used to press the block into a block for 3-5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250-350 MPa for 4-6 minutes. Finally, it is sintered at a temperature of 1500-1550℃ for 10-14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400-1500℃ for 25 hours to obtain a material with a suitable temperature range of 300-1500℃ and a material constant B. The value ranges from 14631 to 17732 K, and the resistivity at 500℃ is 3.25 × 10⁻⁶. 6 – 7.52×10 7 Ω.cm, ln( r ) and 1000 / T linear coefficients of determination R 2 The thermistors have an aging coefficient of 991.72-999.75‰ and an aging coefficient of less than 5% after aging at 1500℃.

[0009] The present invention relates to a rare earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control, and a method for preparing the same. This thermistor can be used to manufacture high-performance high-temperature thermistors with high upper temperature limits and adjustable performance.

[0010] This invention discloses a rare-earth oxide high-temperature thermistor material suitable for temperature measurement and control in aero-engines, and its preparation method. The thermistor material uses five rare-earth oxides selected from terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, and lutetium trioxide, along with tantalum pentoxide and niobium pentoxide, and transition metal oxides vanadium pentoxide, tungsten trioxide, or hafnium dioxide. The mixture is then subjected to mixing, grinding, calcination, cold isostatic pressing, high-temperature sintering, and electrode coating to obtain a high-performance high-temperature thermistor with a high upper temperature limit. Through a high-entropy strategy at the A-site and doping with transition ions and niobium ions at the B-site, the high-temperature structural stability of the material is improved, stabilizing the resistance-temperature relationship at high temperatures. This material can be used to manufacture thermistors with adjustable electrical properties.

[0011] This invention starts from the semiconductor properties, high temperature resistance, high melting point and high resistivity of rare earth tantalate ceramics, and designs and synthesizes high-performance rare earth oxide high-temperature thermistor materials that can be used at temperatures of 300-1500℃ by using A-site high entropy strategy and B-site ion doping.

[0012] Compared with the prior art, the present invention has the following advantages: The rare-earth oxide high-temperature thermistor material described in this invention is suitable for extreme temperature measurement and control. Its applicable temperature range is 300-1500℃, the material constant B value ranges from 14631 to 17732 K, and its resistivity at 500℃ is 3.25 × 10⁻⁶ K. 6 – 7.52×10 7 Ω.cm, ln( r ) and 1000 / T linear coefficients of determination R 2 With a strength of 991.72-999.75‰ and an aging coefficient of less than 5% after aging at 1500℃, it is suitable for manufacturing new high-performance high-temperature thermistors with high upper limit temperatures.

[0013] The rare-earth oxide high-temperature thermistor material and its preparation method suitable for extreme temperature measurement and control described in this invention employ a solid-state method with a molar ratio of RE:Ta:Nb = 2:1:1 or RE:Ta:Nb:TM = Weigh out in a 3:1:1:1 ratio, where RE represents five rare earth elements (Tb, Dy, Ho, Er, Tm, Yb, or Lu) in equal molar amounts, and TM represents transition metal elements (V, W, or Hf). Mix five rare earth oxides (terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, or lutetium trioxide) with tantalum pentoxide and niobium pentoxide, and transition metal oxides (vanadium pentoxide, tungsten trioxide, or hafnium dioxide) in an agate mortar. Grind, calcine, mix, and grind again to obtain a negative temperature coefficient thermistor powder. Press the powder into blocks, cold isostatically press, sinter at high temperature, and then coat both sides with high-temperature platinum paste electrodes to obtain a high-temperature thermistor. The resulting material constant B... The value ranges from 14631 to 17732 K, and the resistivity at 500℃ is 3.42 × 10⁻⁶ K. 6 – 7.70×10 7 Ω.cm, ln( r ) and 1000 / T linear coefficients of determination R 2 The aging coefficient is 996.32-999.75‰, and the aging coefficient after aging at 1500℃ is less than 5%. It has the advantages of stable performance, high accuracy, high sensitivity and good consistency, and is suitable for manufacturing high-performance thermistors. The specific performance parameters of some materials are shown in Table 1. Table 1 Attached Figure Description

[0014] Figure 1 The X-ray diffraction pattern of the thermistor material of the present invention; Figure 2 The resistance-temperature characteristic curve of the thermistor of this invention is shown. Detailed Implementation Example 1

[0015] Preparation of (HoErTmYbLu) 1 / 5 (TaNb) 1 / 2 : a. Mole bis (HoErTmYbLu) 1 / 5 (TaNb) 1 / 2 The raw materials holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide and niobium pentoxide were respectively placed in an agate mortar and mixed, ground for 7 hours, then calcined at 1330℃ for 7 hours, and ground again for 9 hours to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at 15 kg / cm³. 2 The pressure is used to press the block into a block for 5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250 MPa for 6 minutes. Finally, it is sintered at a temperature of 1530℃ for 14 hours to obtain a disc-shaped high-density ceramic. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1500℃. = 14661 K, resistivity at 500℃ is 7.52×10 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 997.15‰, and the aging coefficient is 3.4% after aging at 1500℃. Example 2

[0016] Preparation of (DyErTmYbLu) 1 / 5 (TaNb) 1 / 2 : a. Molecular weight (DyErTmYbLu) 1 / 5 (TaNb) 1 / 2 Raw materials dysprosium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, and niobium pentoxide were respectively placed in an agate mortar and mixed, ground for 7 hours, then calcined at 1330℃ for 7 hours, and ground again for 9 hours to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at 15 kg / cm³. 2 The pressure is used to press the block into a block for 5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250 MPa for 6 minutes. Finally, it is sintered at a temperature of 1530℃ for 14 hours to obtain a disc-shaped high-density ceramic. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1500℃. = 14891 K, resistivity at 500℃ is 7.45 × 10⁻⁶ 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 993.35‰, and the aging coefficient of the high-temperature thermistor is 4.4% after aging at 1500℃. Example 3

[0017] Preparation of (TbErTmYbLu) 1 / 5(TaNb) 1 / 2 : a. Molecular weight (TbErTmYbLu) 1 / 5 (TaNb) 1 / 2 The raw materials terbium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide and niobium pentoxide were respectively placed in an agate mortar and mixed, ground for 7 hours, then calcined at 1330℃ for 7 hours, and ground again for 9 hours to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at 15 kg / cm³. 2 The pressure is used to press the block into a block for 5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250 MPa for 6 minutes. Finally, it is sintered at a temperature of 1530℃ for 14 hours to obtain a disc-shaped high-density ceramic. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1500℃. = 15711 K, resistivity at 500℃ is 7.30 × 10⁻⁶ K. 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 994.52‰, and the aging coefficient is 3.9% after aging at 1500℃. Example 4

[0018] Preparation of (HoErTmYbLu) 1 / 5 (TaNbV) 1 / 3 : a. Mole bis (HoErTmYbLu) 1 / 5 (TaNbV) 1 / 3 The raw materials holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and vanadium pentoxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1340℃ for 6.5 h, and ground again for 8.5 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1540℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1450℃. = 17128 K, resistivity at 500℃ is 3.28 × 10⁻⁶ K. 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 998.83‰, and the aging coefficient of the high-temperature thermistor is 2.3% after aging at 1500℃. Example 5

[0019] Preparation of (DyErTmYbLu) 1 / 5 (TaNbV) 1 / 3 : a. Molecular weight (DyErTmYbLu) 1 / 5 (TaNbV) 1 / 3 The raw materials dysprosium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and vanadium pentoxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1340℃ for 6.5 h, and ground again for 8.5 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1540℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1450℃. = 17423 K, resistivity at 500℃ is 3.22×10 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 997.32‰, and the aging coefficient of the high-temperature thermistor is 3.4% after aging at 1500℃. Example 6

[0020] Preparation of (TbErTmYbLu) 1 / 5 (TaNbV) 1 / 3 : a. Molecular weight (TbErTmYbLu) 1 / 5 (TaNbV) 1 / 3The raw materials terbium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and vanadium pentoxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1340℃ for 6.5 h, and ground again for 8.5 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1540℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1450℃. = 17732 K, resistivity at 500℃ is 3.16×10 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 992.14‰, and the aging coefficient of the high-temperature thermistor is 3.2% after aging at 1500℃. Example 7

[0021] Preparation of (HoErTmYbLu) 1 / 5 (TaNbW) 1 / 3 : a. Mole bis (HoErTmYbLu) 1 / 5 (TaNbW) 1 / The raw materials holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and tungsten trioxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1350℃ for 6.5 h, and ground again for 9 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1550℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1450℃. = 17118 K, resistivity at 500℃ is 2.61×10 7Ω.cm, ln r and 1000 / T The linear coefficient of determination is 991.89‰, and the aging coefficient of the high-temperature thermistor is 4.5% after aging at a temperature of 1500℃. Example 8

[0022] Preparation of (DyErTmYbLu) 1 / 5 (TaNbW) 1 / 3 : a. Molecular weight (DyErTmYbLu) 1 / 5 (TaNbW) 1 / 3 The raw materials dysprosium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and tungsten trioxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1350℃ for 6.5 h, and ground again for 9 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1550℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1450℃. = 17341 K, resistivity at 500℃ is 2.46×10 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 992.45‰, and the aging coefficient of the high-temperature thermistor is 4.9% after aging at a temperature of 1500℃. Example 9

[0023] Preparation of (TbErTmYbLu) 1 / 5 (TaNbW) 1 / 3 : a. Molecular weight (TbErTmYbLu) 1 / 5 (TaNbW) 1 / 3 The raw materials terbium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and tungsten trioxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1350℃ for 6.5 h, and ground again for 9 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1550℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1450℃. = 17583 K, resistivity at 500℃ is 2.42×10 7 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 991.72‰, and the aging coefficient of the high-temperature thermistor is 3.4% after aging at a temperature of 1500℃. Example 10

[0024] Preparation of (HoErTmYbLu) 1 / 5 (TaNbHf) 1 / 3 : a. Mole bis (HoErTmYbLu) 1 / 5 (TaNbHf) 1 / 3 The molar ratio of holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, lutetium oxide, tantalum pentoxide, niobium pentoxide, and hafnium oxide was determined. The raw materials were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1350℃ for 6.5 h, and ground again for 8 h to obtain a dispersed pre-calcined powder. b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1550℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1500℃. = 14631 K, resistivity at 500℃ is 3.42×10 6 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 999.75‰, and the aging coefficient is 1.1% after aging at 1500℃. Example 11

[0025] Preparation of (DyErTmYbLu) 1 / 5 (TaNbHf) 1 / 3 : a. Molecular weight (DyErTmYbLu) 1 / 5 (TaNbHf) 1 / 3 The raw materials dysprosium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and hafnium trioxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1350℃ for 6.5 h, and ground again for 8 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1550℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1500℃. = 14723 K, resistivity at 500℃ is 3.34×10 6 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 998.23‰, and the aging coefficient of the high-temperature thermistor is 2.1% after aging at 1500℃. Example 12

[0026] Preparation of (TbErTmYbLu) 1 / 5 (TaNbHf) 1 / 3 : a. Molecular weight (TbErTmYbLu) 1 / 5 (TaNbHf) 1 / 3 The raw materials terbium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, lutetium trioxide, tantalum pentoxide, niobium pentoxide and hafnium trioxide were weighed separately, placed in an agate mortar and mixed, ground for 7.5 h, then calcined at 1350℃ for 6.5 h, and ground again for 8 h to obtain a dispersed pre-calcined powder; b. The powder obtained in step a is processed at a concentration of 17.5 kg / cm³. 2 The pressure is used to press the block into a block for 3.5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 275 MPa for 4.5 minutes. Finally, it is sintered at 1550℃ for 14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400℃ for 25 hours to obtain a material constant B with a temperature range of 300-1500℃. = 14832 K, resistivity at 500℃ is 3.26×10 6 Ω.cm, ln r and 1000 / T The linear coefficient of determination is 997.37‰, and the aging coefficient of the high-temperature thermistor is 1.7% after aging at 1500℃.

[0027] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto.

Claims

1. A rare-earth oxide high-temperature thermistor material suitable for extreme temperature measurement and control, characterized in that, This material is based on high-entropy rare-earth tantalates, with niobium and TM ions incorporated at the B-site tantalum ion sites. RE represents five rare-earth elements: Tb, Dy, Ho, Er, Tm, Yb, or Lu; TM represents transition metal elements: V, W, or Hf. The raw material rare-earth oxides are five selected from terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide, and lutetium trioxide, respectively, combined with tantalum pentoxide, niobium pentoxide, and the TM transition metal oxides vanadium pentoxide, tungsten trioxide, or hafnium dioxide. The specific operation is carried out according to the following steps: a. Weigh out the rare earth elements in a molar ratio of RE: Ta: Nb = 2:1:1 or RE: Ta: Nb: TM = 3:1:1:1, where RE is five rare earth elements in equimolar amounts of Tb, Dy, Ho, Er, Tm, Yb or Lu, and TM is transition metal elements V, W or Hf. Mix five rare earth oxides (terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide or lutetium trioxide) with tantalum pentoxide and niobium pentoxide, and transition metal oxides (vanadium pentoxide, tungsten trioxide or hafnium dioxide) in an agate mortar, grind for 7-9 h, then calcine at 1300-1350℃ for 3-5 h, and grind again for 6-8 h to obtain a dispersed pre-calcined powder. b. The pre-calcined powder obtained in step a is processed at a concentration of 15-25 kg / cm³. 2 The pressure is used to press the block into a block for 3-5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250-350 MPa for 4-6 minutes. Finally, it is sintered at a temperature of 1500-1550℃ for 10-14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400-1500℃ for 25 hours. This yields a material with an applicable temperature range of 300-1500℃, a material constant B value ranging from 14631 to 17732 K, and a resistivity of 3.25 × 10⁻⁶ K at 500℃. 6 – 7.52×10 7 Ω.cm, ln( ρ ) and 1000 / T The linear coefficient of determination R 2 The thermistors have an aging coefficient of 991.72-999.75‰ and an aging coefficient of less than 5% after aging at 1500℃.

2. A method for preparing rare earth oxide high-temperature thermistor materials suitable for extreme temperature measurement and control, characterized in that... Follow these steps: a. Weigh out the rare earth elements in a molar ratio of RE: Ta: Nb = 2:1:1 or RE: Ta: Nb: TM = 3:1:1:1, where RE is five rare earth elements in equimolar amounts of Tb, Dy, Ho, Er, Tm, Yb or Lu, and TM is transition metal elements V, W or Hf. Mix five rare earth oxides (terbium trioxide, dysprosium trioxide, holmium trioxide, erbium trioxide, thulium trioxide, ytterbium trioxide or lutetium trioxide) with tantalum pentoxide and niobium pentoxide, and transition metal oxides (vanadium pentoxide, tungsten trioxide or hafnium dioxide) in an agate mortar, grind for 7-9 h, then calcine at 1300-1350℃ for 3-5 h, and grind again for 6-8 h to obtain a dispersed pre-calcined powder. b. The pre-calcined powder obtained in step a is processed at a concentration of 15-25 kg / cm³. 2 The pressure is used to press the block into a block for 3-5 minutes. The formed block is then subjected to cold isostatic pressing at a pressure of 250-350 MPa for 4-6 minutes. Finally, it is sintered at a temperature of 1500-1550℃ for 10-14 hours to obtain a circular high-density ceramic block. c. Coat both sides of the sintered circular high-density ceramic block from step b with high-temperature platinum paste electrodes, then anneal at 1400-1500℃ for 25 hours. This yields a material with an applicable temperature range of 300-1500℃, a material constant B value ranging from 14631 to 17732 K, and a resistivity of 3.25 × 10⁻⁶ at 500℃. 6 – 7.52×10 7 Ω.cm, ln( ρ ) and 1000 / T The linear coefficient of determination R 2 The thermistors have an aging coefficient of 991.72-999.75‰ and an aging coefficient of less than 5% after aging at 1500℃.

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