High-stability negative temperature coefficient thermistor material suitable for wide temperature range measurement and control and preparation method thereof
By fabricating perovskite-structured Y-Mn-Ni-O ceramic NTC thermistors, the problem of narrow temperature measurement range of NTC thermistors was solved, achieving high stability and low resistivity fluctuation over a wide temperature range of -193℃ to 800℃, making them suitable for temperature detection in low-temperature, deep-sea, and aerospace applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-28
- Publication Date
- 2026-04-14
AI Technical Summary
Existing negative temperature coefficient (NTC) thermistors have a narrow temperature measurement range, which makes them unable to work properly in extreme temperature environments, increasing system complexity and hardware costs. Furthermore, the nonlinear characteristics of the materials lead to measurement errors.
Using Y2O3, MnO2 and NiO as raw materials, perovskite-structured Y-Mn-Ni-O ceramic NTC thermistors were prepared by solid-state method. Through grinding, calcination, molding and high-temperature sintering, the temperature measurement range was extended to -193℃ to 800℃, and the electrodes were prepared by platinum paste coating.
It achieves high stability and low resistivity fluctuation over a wide temperature range, with a resistance change rate of less than 2.24%, making it suitable for temperature detection in low-temperature, deep-sea, and aerospace fields.
Smart Images
Figure CN121850661A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a high-stability negative temperature coefficient (NTC) thermistor material suitable for wide temperature range measurement and control, and its preparation method. Based on the electrical performance parameters of this material, it is suitable for temperature detection fields such as low temperature, deep sea, and aerospace. Background Technology
[0002] A negative temperature coefficient (NTC) thermistor is a temperature sensor whose resistance decreases as temperature increases. NTC thermistors can be categorized according to their temperature range: low-temperature (below -60°C), medium-temperature (above -60°C, below 300°C), and high-temperature (above 300°C). NTC thermistors offer advantages such as high sensitivity, fast response, small size, and low cost, and are widely used in temperature measurement and control, voltage regulation, compensation, surge current suppression, and many other fields.
[0003] In practical applications, the narrow temperature measurement range of negative temperature coefficient (NTC) thermistors can limit their application scenarios, posing potential risks to measurement accuracy and increasing the complexity of system design. In environments such as industrial furnaces, high-temperature engines, or extremely low-temperature experiments, if the temperature exceeds the thermistor's range, the sensor will malfunction or fail to provide valid data, thus limiting its application in these fields. Furthermore, when the measured temperature approaches the thermistor's range limits, the nonlinear characteristics of the material may intensify, causing the resistance-temperature relationship to deviate from the ideal model and introducing significant measurement errors. System design must accurately predict the range of ambient temperature changes and may require deploying multiple thermistors with different ranges for coverage, increasing hardware costs and system complexity. Additionally, to avoid exceeding the range, over-temperature protection or alarm circuits are often required, further increasing design complexity. Summary of the Invention
[0004] The purpose of this invention is to provide a highly stable negative temperature coefficient thermistor material suitable for wide temperature range measurement and control, and its preparation method. This material is prepared from Y₂O₃, MnO₂, and NiO using a solid-state method, and is produced through grinding, calcination, molding, and high-temperature sintering to obtain a perovskite-structured Y-Mn-Ni-O ceramic NTC thermistor. Its electrical performance parameters are: temperature range: -193℃ to 800℃, resistivity ρ 350℃ = 110.15 - 317.10 Ω·cm, material constant B 100 / 350 = 3660.75 - 4310.29 K, activation energy E a=0.315-0.371 eV, resistance change rate ∆R / R0≤2.24%. The NTC thermistor described in this invention can be used for temperature monitoring and control in environments ranging from -193 to 800℃. It has a significant negative temperature coefficient (NTC) characteristic, a wide temperature measurement range, stable material properties, and good aging resistance. It is suitable for temperature detection fields such as low temperature, deep sea, and aerospace.
[0005] The present invention discloses a highly stable negative temperature coefficient thermistor material suitable for wide temperature range measurement and control. This material is made from Y₂O₃, MnO₂, and NiO as raw materials through grinding, calcination, molding, and high-temperature sintering to obtain a perovskite-structured Y-Mn-Ni-O ceramic material. The specific operation is carried out according to the following steps: a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.95-0.8:0.05-0.2, place them in an agate mortar, mix and grind for 6-10 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at a temperature of 1000℃-1100℃ for 1-6 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 2-8 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed under a pressure of 280 MPa-350 MPa for 140 s-180 s to obtain the molded block. e. Sintering: Place the formed block from step d into a temperature of 1150℃-1350℃ for 4-10 hours, and cool it to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 800℃-1200℃ for 20-40 min to obtain a negative temperature coefficient thermistor material.
[0006] A method for preparing a highly stable NTC thermistor material suitable for wide temperature range measurement and control is carried out according to the following steps: a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.95-0.8:0.05-0.2, place them in an agate mortar, mix and grind for 6-10 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at a temperature of 1000℃-1100℃ for 1-6 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 2-8 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed under a pressure of 280 MPa-350 MPa for 140 s-180 s to obtain the molded block. e. Sintering: Place the formed block from step d into a temperature of 1150℃-1350℃ for 4-10 hours, and cool it to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 800℃-1200℃ for 20-40 min to obtain a negative temperature coefficient thermistor material.
[0007] Compared with the prior art, the present invention has the following advantages: Wide temperature testing range: -193℃ to 800℃; Small resistivity fluctuation: ρ 350℃ =110.15-317.10Ω·cm; The B value is adjustable: B 100 / 350 =3660.75-4310.29 K; Small rate of change of resistance: ∆R / R0≤2.24%. Attached Figure Description
[0008] Figure 1 The curves showing the resistance change rate of the thermistor of the present invention are shown, where the curve with x=0.05 corresponds to the sample of Example 1, the curve with x=0.1 corresponds to the sample of Example 2, the curve with x=0.15 corresponds to the sample of Example 3, and the curve with x=0.2 corresponds to the sample of Example 4. Detailed Implementation
[0009] The present invention will be further described in detail below with reference to the embodiments, but is not limited to the embodiments given. Example 1
[0010] a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.95:0.05, place them in an agate mortar, mix and grind for 6 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at 1000℃ for 2 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 2 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed at 280 MPa for 140 s to obtain the molded block. e. Sintering: The block formed in step d is sintered at 1150℃ for 4 hours and then cooled to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 800℃ for 20 min; the negative temperature coefficient (NTC) thermistor material prepared by the electrodes is subjected to electrical performance testing.
[0011] The resistance was tested at 100℃ and 350℃ respectively, and the value of B was calculated according to equation (1).
[0012]
[0013] The test performance is shown in Table 1.
[0014] As shown in Table 1, YMn 0.95 Ni 0.05 The temperature measurement range of O3 thermistor ceramic material is -193℃ to 800℃, and its resistivity ρ 350℃ It is 317.10 Ω·cm, and the material constant B 100 / 350 It is 4310.29 K, activation energy E a It is 0.371 eV, and the rate of change of resistance ∆R / R0 is 2.24%. Example 2
[0015] a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.9:0.1, place them in an agate mortar, mix and grind for 7 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at 1040℃ for 3 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 4 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed at 300 MPa for 150 s to obtain the molded block. e. Sintering: The block formed in step d is sintered at 1250℃ for 6 hours and then cooled to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 1000℃ for 30 min; the negative temperature coefficient (NTC) thermistor material prepared by the electrodes is tested for electrical properties.
[0016] The resistance was tested at 100℃ and 350℃ respectively, and the value of B was calculated according to equation (1).
[0017]
[0018] The test performance is shown in Table 2.
[0019] As shown in Table 2, YMn 0.9 Ni 0.1 The temperature measurement range of O3 thermistor ceramic material is -193℃ to 800℃, and the resistivity ρ 350℃ It is 153.52 Ω·cm, and the material constant B 100 / 350 It is 4235.70 K, activation energy E a It is 0.365 eV, and the rate of change of resistance ∆R / R0 is 1.26%. Example 3
[0020] a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.85:0.15, place them in an agate mortar, mix and grind for 8 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at 1070℃ for 4 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 6 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed at 330 MPa for 160 s to obtain the molded block. e. Sintering: The block formed in step d is sintered at 1300℃ for 8 hours and then cooled to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 1100℃ for 35 min; the negative temperature coefficient (NTC) thermistor material prepared by the electrodes is tested for electrical properties.
[0021] The resistance was tested at 100℃ and 350℃ respectively, and the value of B was calculated according to equation (1).
[0022]
[0023] The test performance is shown in Table 3.
[0024] As shown in Table 3, YMn 0.85 Ni 0.15 The temperature measurement range of O3 thermistor ceramic material is -193℃ to 800℃, and its resistivity ρ 350℃ It is 121.42 Ω·cm, and the material constant B 100 / 350 It is 3810.91 K, activation energy E a It is 0.328 eV, and the rate of change of resistance ∆R / R0 is 0.83%. Example 4
[0025] a. Powder ratio: Weigh the Y2O3:MnO2:NiO powders according to the molar ratio of Y2O3:MnO2:NiO = 1:0.8:0.2, place them in an agate mortar, mix and grind for 10 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at 1100℃ for 6 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 8 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed at 350 MPa for 180 s to obtain the molded block. e. Sintering: The block formed in step d is sintered at 1350℃ for 10 hours and then cooled to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 1200℃ for 40 min; the negative temperature coefficient (NTC) thermistor material prepared by the electrodes is subjected to electrical performance testing.
[0026] The resistance was tested at 100℃ and 350℃ respectively, and the value of B was calculated according to equation (1).
[0027]
[0028] The test performance is shown in Table 4.
[0029] As shown in Table 4, YMn 0.8 Ni 0.2 The temperature measurement range of O3 thermistor ceramic material is -193℃ to 800℃, and the resistivity ρ 350℃It is 110.15 Ω·cm, and the material constant B 100 / 350 It is 3660.75 K, activation energy E a It is 0.315 eV, and the rate of change of resistance ∆R / R0 is 0.53%. Example 5
[0030] All negative temperature coefficient (NTC) thermistor materials prepared in Examples 1-4 that are suitable for wide temperature range measurement and control are perovskite structures. All ceramic sheets show good compactness in microstructure, good ceramic formation, consistency and reproducibility, wide temperature testing range, stable material properties and good anti-aging properties.
[0031] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformations or substitutions fall within the scope of protection of the present invention.
Claims
1. A highly stable negative temperature coefficient thermistor material suitable for wide temperature range measurement and control, characterized in that... This material is made from Y₂O₃, MnO₂, and NiO as raw materials through grinding, calcination, molding, and high-temperature sintering to obtain a perovskite-structured Y-Mn-Ni-O ceramic material. The specific operation is carried out according to the following steps: a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.95-0.8:0.05-0.2, place them in an agate mortar, mix and grind for 6-10 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at a temperature of 1000℃-1100℃ for 1-6 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 2-8 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed under a pressure of 280 MPa-350 MPa for 140 s-180 s to obtain the molded block. e. Sintering: Place the formed block from step d into a temperature of 1150℃-1350℃ for 4-10 hours, and cool it to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 800℃-1200℃ for 20-40 min to obtain a negative temperature coefficient thermistor material.
2. A method for preparing a highly stable negative temperature coefficient thermistor material suitable for wide temperature range measurement and control, characterized in that... Follow these steps: a. Powder ratio: Weigh the powders according to the molar ratio Y2O3:MnO2:NiO = 1:0.95-0.8:0.05-0.2, place them in an agate mortar, mix and grind for 6-10 hours to obtain Y-Mn-Ni-O mixed powder; b. Calcination: The Y-Mn-Ni-O mixed powder obtained in step a is calcined at a temperature of 1000℃-1100℃ for 1-6 hours to obtain Y-Mn-Ni-O powder with perovskite structure; c. Grinding: Place the perovskite Y-Mn-Ni-O powder calcined in step b into an agate mortar and grind for 2-8 hours; d. Molding: The powder ground in step c is molded into a green material with a diameter of 10 mm. Then, it is vacuum sealed and cold isostatically pressed under a pressure of 280 MPa-350 MPa for 140 s-180 s to obtain the molded block. e. Sintering: Place the formed block from step d into a temperature of 1150℃-1350℃ for 4-10 hours, and cool it to room temperature to obtain ceramic block material; f. Electrode preparation: Platinum paste is coated on both sides of the ceramic bulk material obtained in step e, and sintered at 800℃-1200℃ for 20-40 min to obtain a negative temperature coefficient thermistor material.