Gallium and zinc doped copper-cobalt spinel ceramic temperature sensor and preparation method and application thereof

Abstract

The invention discloses a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor and a preparation method and application thereof, and belongs to the technical field of temperature sensors. The preparation method of the temperature sensor comprises the following steps: preparing a copper-cobalt spinel precursor by using bivalent copper salt and trivalent cobalt salt of which the molar ratio of copper ions to cobalt ions is 1: 2; the preparation method comprises the following steps: mixing and grinding a copper-cobalt spinel precursor, an inorganic zinc compound and gallium oxide to form mixed powder, carrying out compression molding to prepare a thermistor material precursor, calcining the thermistor material precursor in a muffle furnace at 1000-1400 DEG C for 2-6 hours to obtain a spinel thermistor ceramic material, and preparing the temperature sensor from the spinel thermistor ceramic material, the molar ratio of zinc ions in the inorganic zinc compound to gallium ions in the gallium oxide is 1: 2, and the molar ratio of copper ions in the cupric salt to the zinc ions in the inorganic zinc compound is (5-9): (1-5). The temperature sensor is low in preparation raw material cost and simple in process, can be applied to temperature measurement in a wide-range low-temperature region, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature temperature sensors, and also to the technical field related to semiconductor materials and special electronic materials. Specifically, it relates to a gallium and zinc-doped copper-cobalt spinel ceramic temperature sensor and its preparation method and application, which are applied to temperature monitoring in a wide range of low-temperature zones. Background Art

[0002] With the widespread application of cryogenic technology in the fields of biomedicine, aerospace, agricultural processing, etc., there is a strong demand for low-cost, high-performance temperature sensors for monitoring low-temperature areas. At present, the temperature sensors commonly used for monitoring low-temperature areas include platinum resistance temperature sensors, rhodium iron resistance temperature sensors, germanium resistance temperature sensors, diode temperature sensors, etc. Although platinum resistance temperature sensors have high temperature monitoring accuracy and a wide monitoring temperature range in low-temperature environments, because their core material is the precious metal platinum, they are expensive and difficult to use on a large scale. Rhodium iron resistance temperature sensors and germanium resistance temperature sensors have obvious price advantages compared to platinum resistance temperature sensors, but are usually used for ultra-low temperature monitoring below 27K, and the monitoring range of low-temperature areas (<0°C) is limited. Diode temperature sensors are easily affected by magnetic fields and their application conditions are limited.

[0003] Compared with traditional temperature-sensitive materials, spinel thermistor materials have the advantages of high temperature coefficient, fast response speed, small magnetic field influence, stable structure and low cost, making them promising candidate materials for high-precision temperature monitoring. Although many spinel temperature sensors (general formula of spinel structure: AB2O4) have been studied for temperature monitoring, there are still huge challenges in meeting the requirements of temperature monitoring in a wide range and low temperature zones at the same time. In the prior art, many researchers have improved the performance of spinel temperature sensors. For example, the Xinjiang Institute of Physics and Chemistry of the Chinese Academy of Sciences disclosed a spinel thermistor material for high-temperature and wide-temperature-range temperature measurement and its preparation method in a patent document with publication number CN116621573A, which directly uses high-temperature calcination of magnesium-aluminum spinel and manganese-iron spinel to obtain Mg. x Mn 1-x Al 2x Fe 2(1-x)O4 spinel-type thermistor material can be used to monitor a temperature range of 0-600°C, but it is difficult to meet the requirements of high-precision temperature monitoring in low-temperature zones (<0°C); Chongqing Materials Research Institute Co., Ltd. disclosed a spinel-phase high-entropy thermistor material and a preparation method thereof in a patent document with publication number CN112811891A, and the Guangdong Academy of Sciences' Resource Utilization and Rare Earth Development Research disclosed a cerium- and manganese-doped magnesium aluminum spinel fluorescent temperature sensing material and its application in temperature measurement in a patent document with publication number CN114292648A. Both of them improve the temperature monitoring performance of thermistors by doping the A position of the spinel structure, but neither of them studies the monitoring performance and monitoring range in the low-temperature zone (<0°C). In addition, relevant literature has found that spinel-structured NiMn2O4 thermosensitive materials can be used to monitor temperatures in the range of -30°C to 145°C (Sensor Review., 2022, 42(2): 177-186.), and spinel-structured CuMn2O4 thermistor materials have a temperature monitoring range of 20-80°C (Ceramics International., 2019, 45(8): 10565-10571). However, both are difficult to monitor temperatures in lower temperature ranges. Therefore, it is of great significance to develop a low-cost, highly sensitive, and wide-range low-temperature temperature monitoring thermosensitive material and preparation method. Summary of the Invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a gallium and zinc doped copper cobalt spinel ceramic temperature sensor and its preparation method and application. The preparation method of the present invention is simple to operate and low in cost. The prepared sensor has a high temperature sensitivity coefficient and has a temperature monitoring range of the mine in the low temperature zone.

[0005] To achieve the above objectives, the technical solutions of the present invention are as follows:

[0006] A method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor comprises the following steps:

[0007] S1. Preparing a copper-cobalt spinel precursor using a divalent copper salt and a trivalent cobalt salt, wherein the molar ratio of copper ions in the divalent copper salt to cobalt ions in the trivalent cobalt salt is 1:2;

[0008] S2. A copper-cobalt spinel precursor, an inorganic zinc compound, and gallium oxide are mixed and ground to form a mixed powder, the mixed powder is molded to prepare a thermistor material precursor, and the thermistor material precursor is placed in a muffle furnace at 1000-1400° C. and calcined for 2-6 hours to obtain a spinel thermistor ceramic material, wherein the molar ratio of zinc ions in the inorganic zinc compound to gallium ions in gallium oxide is 1:2, and the molar ratio of copper ions in the divalent copper salt to zinc ions in the inorganic zinc compound is (5-9):(1-5);

[0009] S3. Using platinum wire as electrode and spinel thermistor ceramic material to prepare temperature sensor.

[0010] As a specific embodiment of the present invention, in step S1, a copper-cobalt spinel precursor is prepared by the following method: divalent copper salt and trivalent cobalt salt are dissolved in deionized water, the pH value of the solution is adjusted to 9-12, and then the solution is placed in a reactor and heated at 120-180°C for 4-12 hours, and finally the copper-cobalt spinel precursor is obtained by filtering, washing and drying.

[0011] In the present invention, the pH value of the solution is adjusted to 9-12, and an alkali solution such as ammonia water or sodium hydroxide can be selected as needed.

[0012] As a specific embodiment of the present invention, the molar ratio of copper ions in the divalent copper salt to zinc ions in the inorganic zinc compound is (6-9):(1-4).

[0013] As a specific embodiment of the present invention, the divalent copper salt is a hydrate of copper chloride, copper nitrate or copper sulfate.

[0014] As a specific embodiment of the present invention, the trivalent cobalt salt is a hydrate of cobalt chloride, cobalt nitrate or cobalt sulfate.

[0015] As a specific embodiment of the present invention, the inorganic zinc compound is zinc oxide or zinc nitrate.

[0016] A gallium and zinc doped copper-cobalt spinel ceramic temperature sensor is prepared by the above method.

[0017] The invention discloses an application of a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor for measuring temperature in a low temperature environment of -80 to 0°C.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The temperature sensor of the present invention has high sensitivity in monitoring the temperature in a wide range of low temperature area (-80° C. to 0° C.) and has good stability.

[0020] The preparation method of the present invention has simple equipment and preparation process, abundant raw material sources and low cost, and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The XRD pattern of the thermistor ceramic material prepared in Example 1;

[0022] Figure 2 This is a scanning electron microscope image of the temperature sensor prepared in Example 1;

[0023] Figure 3 This is the EDS spectrum of the corresponding Cu element of the temperature sensor prepared in Example 1;

[0024] Figure 4 This is the EDS spectrum of the corresponding Zn element of the temperature sensor prepared in Example 1;

[0025] Figure 5 The EDS spectrum of the corresponding Co element of the temperature sensor prepared in Example 1;

[0026] Figure 6 The EDS spectrum of the corresponding Ga element of the temperature sensor prepared in Example 1;

[0027] Figure 7 The EDS spectrum of the corresponding O element of the temperature sensor prepared in Example 1;

[0028] Figure 8 This is a graph showing the relationship between the resistivity logarithm and 1000 / T of the temperature sensor prepared in Example 1;

[0029] Figure 9 This is a graph showing the relationship between the resistivity logarithm and 1000 / T of the temperature sensor prepared in Comparative Example 1. DETAILED DESCRIPTION

[0030] The following examples provide a clear and complete description of the specific embodiments of the present invention. It should be understood that the examples described are merely some, not all, embodiments of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available unless otherwise specified.

[0031] Example 1

[0032] S1. Add 5.65g Co(NO3)3·6H2O and 1.93g Cu(NO3)2·3H2O to 200ml deionized water, then stir for 20min to completely dissolve the solid, then slowly add 0.1mol / L sodium hydroxide solution dropwise to make the pH value of the mixed solution reach 10, then transfer the solution to a polytetrafluoroethylene reactor and seal it, heat it at 150℃ for 12h, filter, wash with alcohol, and dry at 60℃ to obtain a copper-cobalt spinel precursor.

[0033] S2. The copper-cobalt spinel precursor, 0.16 g ZnO, and 0.38 g Ga2O3 were mixed uniformly, ground thoroughly, and then the mixed powder was passed through a 500-mesh sieve. 2.0 g of the mixed powder was obtained by compression molding under 10 MPa to obtain a thermistor material precursor. The thermistor material precursor was then placed in a muffle furnace at 1200° C. and calcined for 3 h to obtain a circular thin-sheet spinel thermistor ceramic material with a diameter of 10 mm and a thickness of 2 mm;

[0034] S3. Using platinum wire as an electrode, the spinel thermistor ceramic material is prepared into a temperature sensor.

[0035] Example 2

[0036] S1. Add 4.942 g of Co(NO3)3·6H2O and 1.69 g of Cu(NO3)2·3H2O to 200 ml of deionized water, and stir for 20 min to completely dissolve the solid. Then, slowly add 0.1 mol / L sodium hydroxide solution dropwise to adjust the pH value of the mixed solution to 10. Then, transfer the solution to a polytetrafluoroethylene reactor and seal it. Heat it at 150 ° C for 12 h, filter, wash with alcohol, and dry at 60 ° C to obtain a copper-cobalt spinel precursor.

[0037] S2. The copper-cobalt spinel precursor, 0.24 g ZnO, and 0.57 g Ga2O3 were mixed uniformly, ground thoroughly, and then the mixed powder was passed through a 500-mesh sieve. 2.0 g of the mixed powder was obtained by compression molding under 10 MPa to obtain a thermistor material precursor. The thermistor material precursor was then placed in a muffle furnace at 1200° C. and calcined for 3 h to obtain a circular thin-sheet spinel thermistor ceramic material with a diameter of 10 mm and a thickness of 2 mm;

[0038] S3. Using platinum wire as an electrode, the spinel thermistor ceramic material is prepared into a temperature sensor.

[0039] Example 3

[0040] S1. Add 4.24 g of Co(NO3)3·6H2O and 1.45 g of Cu(NO3)2·3H2O to 200 ml of deionized water, and stir for 20 min to completely dissolve the solid. Then, slowly add 0.1 mol / L sodium hydroxide solution dropwise to adjust the pH value of the mixed solution to 10. Then, transfer the solution to a polytetrafluoroethylene reactor, seal it, heat it at 150 ° C for 12 h, filter it, wash it with alcohol, and dry it at 60 ° C to obtain a copper-cobalt spinel precursor.

[0041] S2, the copper-cobalt spinel precursor, 0.33g ZnO, and 0.76g Ga2O3 were mixed uniformly, fully ground, and then the mixed powder was passed through a 500-mesh sieve. 2.0g of the mixed powder was obtained by molding under 10MPa to obtain a thermistor material precursor, and then the thermistor material precursor was placed in a muffle furnace at 1200°C for 3h to obtain a circular thin-sheet spinel thermistor ceramic material with a diameter of 10mm and a thickness of 2mm;

[0042] S3. Using platinum wire as an electrode, the spinel thermistor ceramic material is prepared into a temperature sensor.

[0043] Example 4

[0044] S1. Add 6.354 g of Co(NO3)3·6H2O and 2.17 g of Cu(NO3)2·3H2O to 200 ml of deionized water, and stir for 20 min to completely dissolve the solid. Then, slowly add 0.1 mol / L sodium hydroxide solution dropwise to adjust the pH value of the mixed solution to 10. Then, transfer the solution to a polytetrafluoroethylene reactor and seal it. Heat it at 150 ° C for 12 h, filter, wash with alcohol, and dry at 60 ° C to obtain a copper-cobalt spinel precursor.

[0045] S2. The copper-cobalt spinel precursor, 0.08 g ZnO, and 0.19 g Ga2O3 were mixed uniformly, fully ground, and then the mixed powder was passed through a 500-mesh sieve. 2.0 g of the mixed powder was obtained by molding under 10 MPa to obtain a thermistor material precursor. The thermistor material precursor was then placed in a muffle furnace at 1200° C. and calcined for 3 h to obtain a circular thin-sheet spinel thermistor ceramic material with a diameter of 10 mm and a thickness of 2 mm;

[0046] S3. Using platinum wire as an electrode, the spinel thermistor ceramic material is prepared into a temperature sensor.

[0047] Example 5

[0048] S1. Add 7.10 g of Co(NO3)3·6H2O and 2.42 g of Cu(NO3)2·3H2O to 200 ml of deionized water, and stir for 20 min to completely dissolve the solid. Then, slowly add 0.1 mol / L sodium hydroxide solution dropwise to adjust the pH value of the mixed solution to 10. Then, transfer the solution to a polytetrafluoroethylene reactor and seal it. Heat it at 150 ° C for 12 h, filter, wash with alcohol, and dry at 60 ° C to obtain a copper-cobalt spinel precursor.

[0049] S2. The copper-cobalt spinel precursor, 0.81 g ZnO, and 1.87 g Ga2O3 were mixed uniformly, fully ground, and then the mixed powder was passed through a 500-mesh sieve. 2.0 g of the mixed powder was obtained by molding under 10 MPa to obtain a thermistor material precursor. The thermistor material precursor was then placed in a muffle furnace at 1200° C. and calcined for 3 h to obtain a circular thin-sheet spinel thermistor ceramic material with a diameter of 10 mm and a thickness of 2 mm;

[0050] S3. Using platinum wire as an electrode, the spinel thermistor ceramic material is prepared into a temperature sensor.

[0051] Test Example 1

[0052] The spinel thermistor ceramic material prepared in Example 1 of the present invention was subjected to XRD analysis, and the results were as follows: Figure 1 As shown, the diffraction peaks of the prepared spinel thermistor ceramic material basically match those of the standard spinel CuCo2O4 (PDF01-1155), indicating that the spinel thermistor ceramic material mainly presents the crystal structure of CuCo2O4 spinel.

[0053] Figure 2 This is an SEM image of the spinel thermistor ceramic material prepared in Example 1; Figures 3 to 7 The figure shows the EDS elemental spectrum of Cu, Zn, Co, Ga, and O. It can be observed from the figure that all elements are evenly distributed, and there is no phenomenon such as element enrichment, indicating that there is sufficient contact between different atoms.

[0054] Test Example 2

[0055] Take the temperature sensors of Examples 1 to 5, measure their resistance at multiple temperature points within the range of -80°C to 0°C, and calculate their material constants B -80℃ / 0℃ (K), determine the linear relationship between the logarithm of the resistivity and 1000 / T, age the above temperature sensor at a temperature of 500°C for 1000h, measure the resistance before and after aging, and determine its aging coefficient.

[0056] The material constants are calculated as: Among them, R T , R0 are the resistances corresponding to temperature T and initial temperature respectively;

[0057] The calculation formula of the aging coefficient is: Among them, R1 is the resistance value at 0℃ after aging, and R0 is the resistance value at 0℃ before aging;

[0058] The specific test results are shown in Table 1. Figure 8 and Figure 9 .

[0059] Table 1 Performance parameters of the temperature sensors in various embodiments

[0060] Sample / Performance Parameters <![CDATA[Material constant B -80℃ / 0℃ (K)]]> <![CDATA[Coefficient of determination R after linear fitting 2 > Aging coefficient (%) Example 1 1588 0.998 1.76 Example 2 1652 0.991 2.11 Example 3 1620 0.992 2.37 Example 4 1534 0.993 2.16 Example 5 1630 0.988 2.54

[0061] From the table above, we can see that the material constant B of all spinel thermistor ceramic materials is -80℃ / 0℃ Between 1534 and 1652 K, the coefficient of determination after linear fitting R 2 The aging coefficient is greater than 98%, and the aging coefficient is less than 2.54%, which shows that the performance is stable and the sensitivity is high in a wide temperature range of -80 to 0 ° C. Among them, the determination coefficient R after linear fitting of Examples 1 to 4 is 2 are greater than 99%, and the determination coefficient R after linear fitting in Example 1 is 2 and aging coefficient are both optimal.

[0062] The present invention has been disclosed above with reference to preferred embodiments. However, those skilled in the art will appreciate that these embodiments are intended to illustrate the present invention only and are not to be construed as limiting the scope of the present invention. Further improvements may be made without departing from the principles of the present invention, and such improvements are intended to fall within the scope of protection of the present invention.

Claims

1. A method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor, characterized in that: The steps include: S1. Preparing a copper-cobalt spinel precursor using a divalent copper salt and a trivalent cobalt salt, wherein the molar ratio of copper ions in the divalent copper salt to cobalt ions in the trivalent cobalt salt is 1:2; S2. A copper-cobalt spinel precursor, an inorganic zinc compound, and gallium oxide are mixed and ground to form a mixed powder, the mixed powder is molded to prepare a thermistor material precursor, and the thermistor material precursor is placed in a muffle furnace at 1000-1400° C. and calcined for 2-6 hours to obtain a spinel thermistor ceramic material, wherein the molar ratio of zinc ions in the inorganic zinc compound to gallium ions in gallium oxide is 1:2, and the molar ratio of copper ions in the divalent copper salt to zinc ions in the inorganic zinc compound is (5-9):(1-5); S3. Using platinum wire as electrode and spinel thermistor ceramic material to prepare temperature sensor.

2. The method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor according to claim 1, characterized in that: The copper-cobalt spinel precursor is prepared by the following method: dissolving a divalent copper salt and a trivalent cobalt salt in deionized water, then adjusting the pH value of the solution to 9-12, then placing the solution in a reactor and heating it at 120-180° C. for 4-12 hours, and finally filtering, washing, and drying to obtain the copper-cobalt spinel precursor.

3. The method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor according to claim 2, characterized in that: The molar ratio of copper ions in the divalent copper salt to zinc ions in the inorganic zinc compound is (6-9):(1-4).

4. The method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor according to claim 2, characterized in that: The divalent copper salt is a hydrate of copper chloride, copper nitrate or copper sulfate.

5. The method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor according to claim 2, characterized in that: The trivalent cobalt salt is a hydrate of cobalt chloride, cobalt nitrate or cobalt sulfate.

6. The method for preparing a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor according to claim 1, characterized in that: The inorganic zinc compound is zinc oxide or zinc nitrate.

7. A gallium and zinc doped copper-cobalt spinel ceramic temperature sensor, characterized in that: The method is prepared by any one of claims 1 to 6.

8. An application of a gallium and zinc doped copper-cobalt spinel ceramic temperature sensor, characterized in that: The gallium and zinc doped copper-cobalt spinel ceramic temperature sensor according to claim 7 is used for measuring temperature in a low temperature environment of -80 to 0°C.

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