CN111854998A - Temperature sensor - Google Patents
Temperature sensor Download PDFInfo
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- CN111854998A CN111854998A CN201910366138.6A CN201910366138A CN111854998A CN 111854998 A CN111854998 A CN 111854998A CN 201910366138 A CN201910366138 A CN 201910366138A CN 111854998 A CN111854998 A CN 111854998A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/22—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor
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Abstract
The present invention provides a temperature sensor, comprising: a resistance measuring device; and a vanadium dioxide-based single crystal produced by the steps of: heating a raw material containing a vanadium source to a temperature of 950 ℃ to 1150 ℃ in a flowing inert gas atmosphere for 24 hours to 72 hours, and then cooling to room temperature at a speed of not more than 20 ℃/minute to obtain a vanadium dioxide-based single crystal, wherein the vanadium source is an oxygen-containing compound containing no other metal element than vanadium, and wherein vanadium has a valence of +4 or +5, and the molar ratio of oxygen to vanadium is 2: 1 or more; wherein the resistance measuring device is configured for measuring the resistance of the vanadium dioxide based single crystal. The negative temperature coefficient thermistor obtained by the invention has excellent performance parameters, simple preparation process and low price, and is suitable for high-precision temperature detection and temperature compensation within-50 ℃ to 60 ℃.
Description
Technical Field
The invention relates to the field of negative temperature coefficient thermistor materials, in particular to a temperature sensor.
Background
Thermistors are important temperature sensing devices, and are based on the fact that electrical parameters such as resistance and thermoelectric potential of a material regularly change along with the temperature in the temperature change process, and the current temperature is reversely deduced by measuring the electrical parameters of the material at a certain temperature. Thermistors are mainly classified into three categories: positive Temperature Coefficient (PTC) thermistors, Negative Temperature Coefficient (NTC) thermistors, and Critical Temperature Resistors (CTRs).
The thermistor with negative temperature coefficient is mainly formed by sintering oxides of metals such as manganese, cobalt, nickel, copper and the like through a ceramic process, most of the oxides are ternary and above complex oxides, have disordered chemical compositions, and meanwhile, rich domain boundary structures are generated in the sintering process, so that the measurement of the intrinsic resistance of the thermistor is greatly influenced by the factors, and the repeatability of the temperature coefficient of a sample is difficult to ensure. Therefore, a simple material system with a large negative temperature coefficient is sought, which can greatly improve the performance repeatability of the negative temperature coefficient thermistor, is convenient for single crystal growth, can reduce electronic scattering brought by domain boundaries, thereby obtaining an intrinsic resistor determined by the components and the structure of a sample, and is beneficial to realizing the negative temperature coefficient thermistor with high sensitivity and high standardization degree.
Vanadium dioxide is a substance that undergoes an insulator-metal phase transition at a specific temperature. When the temperature is lower than the phase transition temperature, the vanadium dioxide is an insulator phase, and the resistance value of the vanadium dioxide is continuously reduced along with the temperature change, so that the vanadium dioxide has the potential of being used as a negative temperature coefficient thermistor. To date, growing vanadium dioxide thin films on titanium dioxide or sapphire substrates is the main means for preparing large-size vanadium dioxide materials. However, during the growth process, the vanadium dioxide epitaxial film grown on the substrate is usually a polycrystalline film, and the resistance thereof is also seriously affected by extrinsic factors such as grain boundary scattering and defect scattering along with the temperature change, so that the reduction of the resistance during the temperature change is reduced. . In addition, internal stress is easily generated in the thin film, resulting in variation in response to temperature. At present, the preparation of large-size high-quality vanadium dioxide-based single crystals is a prerequisite condition for realizing the application of vanadium dioxide-based thermistors.
Disclosure of Invention
In one aspect, the present invention provides a temperature sensor comprising:
a resistance measuring device; and
a vanadium dioxide-based single crystal produced by the steps of:
heating a raw material containing a vanadium source to a temperature of 950 ℃ to 1150 ℃ for 24 to 72 hours in a flowing inert gas atmosphere, and then cooling to room temperature at a rate of not more than 20 ℃/min to obtain a vanadium dioxide-based single crystal, wherein the vanadium source is an oxygen-containing compound containing no other metal element than vanadium, and wherein vanadium has a valence of +4 or +5, and the molar ratio of oxygen to vanadium is 2: 1 or more,
wherein the resistance measuring device is configured for measuring the resistance of the vanadium dioxide based single crystal.
Preferably, the source of vanadium is selected from the group consisting of: oxides of vanadium, oxygen-containing vanadium salts, vanadium oxyacid salts, and combinations thereof.
Preferably, the source of vanadium is selected from the group consisting of: vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, vanadyl sulfate hydrate, vanadium ammonium sulfate, and combinations thereof.
Preferably, the source comprising vanadium is placed in a semi-open vessel.
Preferably, the semi-open container is a single-opening pipe which is positioned in a horizontal inert gas flow and is obliquely placed, the single-opening pipe is arranged in a way that a pipe orifice is higher than the bottom of the pipe, and the included angle between the length direction and the horizontal plane is 5-35 degrees. More preferably, the length direction of the single-opening tube forms an angle of 20 to 30 ° with the horizontal plane.
Preferably, the flowing inert gas atmosphere comprises convection of an inert gas.
Preferably, the inert gas is selected from the group consisting of: nitrogen, argon, and combinations thereof.
Optionally, the feedstock further comprises a source of a doping element.
Preferably, the vanadium dioxide-based single crystal is a rod-shaped single crystal having a length of 1 mm or more and a diameter of 100 μm or more.
Preferably, the resistance measuring device comprises a voltmeter and an ammeter, and the resistance is calculated by measuring the voltage and the current, wherein two connection points of the voltmeter and the vanadium dioxide-based single crystal are between two connection points of the ammeter and the vanadium dioxide-based single crystal.
Preferably, the vanadium dioxide-based single crystal is fixed on an insulating substrate.
Drawings
In order to more fully illustrate the invention, reference will now be made to the accompanying drawings, which are to be used in either an embodiment or a prior art description, and it is to be noted that the following description of the drawings is only a partial illustration of the invention, and that other drawings may be derived from the drawings provided by those skilled in the art without the benefit of the inventive faculty.
FIG. 1 is a resistance versus temperature relationship of a thermistor provided in accordance with one embodiment of the present invention at-50 deg.C to 60 deg.C.
Fig. 2 is a diagram showing the temperature resistance characteristics of the thermistor in the range of-50 c to 60 c according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a temperature-sensitive sensor provided in accordance with an embodiment of the present invention.
Fig. 4 is a schematic diagram of the arrangement of the apparatus in one embodiment of the invention.
Detailed description of the preferred embodiments
The invention provides a method for preparing a temperature sensor, which uses a large-size high-quality vanadium dioxide-based single crystal as a negative temperature coefficient thermistor.
The present invention provides a temperature sensor, comprising:
a resistance measuring device; and
a vanadium dioxide-based single crystal produced by the steps of:
heating a raw material containing a vanadium source to a temperature of 950 ℃ to 1150 ℃ in a flowing inert gas atmosphere for 24 hours to 72 hours, and then cooling to room temperature at a speed of not more than 20 ℃/minute to obtain a vanadium dioxide-based single crystal, wherein the vanadium source is an oxygen-containing compound containing no other metal element than vanadium, and wherein vanadium has a valence of +4 or +5, and the molar ratio of oxygen to vanadium is 2: 1 or more;
wherein the resistance measuring device is configured for measuring the resistance of the vanadium dioxide based single crystal.
The temperature sensor of the invention uses a large-size vanadium dioxide-based single crystal prepared by a specific method. The method comprises heating a raw material containing a vanadium source to a temperature of 950 ℃ to 1150 ℃ for 24 hours to 72 hours in a flowing inert gas atmosphere, and then cooling to room temperature at a rate of not more than 20 ℃/min to obtain a vanadium dioxide-based single crystal,
wherein the vanadium source is an oxygen-containing compound containing no other metal element than vanadium, and wherein vanadium has a valence of +4 or +5, and the molar ratio of oxygen to vanadium is 2: 1 or more.
By this method, a large-sized vanadium dioxide-based single crystal in a non-thin film form can be produced.
The vanadium dioxide based single crystal has good negative temperature coefficient thermistor characteristics.
The vanadium dioxide-based single crystal is produced by heating a raw material containing a vanadium source at a high temperature for a long time in a flowing inert gas atmosphere. The vanadium dioxide-based single crystal is not in the form of a thin film and can have a maximum dimension of the order of millimeters.
In order to produce a high-purity vanadium dioxide-based single crystal, the vanadium source of the present invention is an oxygen-containing compound containing no other metal element than vanadium, and wherein vanadium has a valence of +4 or +5 and the molar ratio of oxygen to vanadium is 2: 1 or more. Without being bound to any theory, the principle of such a vanadium source to form a vanadium dioxide-based single crystal is as follows: during heating, the vanadium source in the raw material decomposes vanadium and oxygen, producing vanadium-oxygen compounds. The stable phase of the vanadium-oxygen compound under the high-temperature oxygen-deficient condition is VO 2. Thus, VO can be produced by vanadium source decomposition2Phase of simultaneous VO2The phase can generate solid-gas conversion at high temperature, and in the growth container, the continuous inert convection current can drive VO2The evaporation-deposition growth process of gaseous substances can be greatly improvedVO with high size and quality2And (3) single crystal. The atmosphere of the preparation method of the vanadium dioxide-based single crystal is oxygen-deficient, so that if a low-valence vanadium source is selected, the vanadium dioxide-based single crystal cannot be further oxidized under the oxygen-deficient condition to form VO2Species of the species. In addition, if the molar ratio of oxygen to vanadium is less than 2: 1 per mole, VO formation is also not favored2And (3) single crystal. Alternatively, the molar ratio of oxygen to vanadium per mole may be 2: 1, 3: 1, 4: 1, etc. The redundant oxygen in the vanadium source and non-metallic elements (such as N, S, C, H and the like) except oxygen can not react on VO under the condition of flowing inert gas atmosphere2The crystals of (2) have an adverse effect.
From the viewpoint of easy decomposition of the vanadium source, the vanadium source is preferably selected from the group consisting of: oxides of vanadium, oxygen-containing vanadium salts, vanadium oxyacid salts, and combinations thereof. Preferably, the source of vanadium is selected from the group consisting of: vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, vanadyl sulfate hydrate, vanadium ammonium sulfate, and combinations thereof. Still more preferably, the source of vanadium is selected from the group consisting of: vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, and combinations thereof.
The vanadium source is typically in powder form, but may be in other forms. The invention has no special requirement on the granularity of the vanadium source.
The raw material containing a vanadium source may contain only a vanadium source, or may contain a source of a doping element other than a vanadium source. When the source of the doping element is contained, the doping element is doped in the vanadium dioxide single crystal, the whole crystal structure of the vanadium dioxide single crystal is not influenced, and the obvious adjustment effect on the phase transition temperature of the insulator-metal is generated.
The source of doping elements may be selected from the group consisting of: a molybdenum source, a tungsten source, a titanium source, an aluminum source, a niobium source, a chromium source, and combinations thereof. These doping element sources can also generally be in powder form and homogeneously mixed with the vanadium source in powder form. The mass ratio of the source of doping element to the source of vanadium may be in the range 0.01: 10 to 1: 10, for example 0.5: 10. The doping element source is generally an oxygen-containing compound containing no other metal element than the doping element or a salt that is easily decomposed into an oxygen-containing compound. For example, molybdenum trioxide or ammonium molybdate may be used as the molybdenum source.
After the raw materials are placed, the vanadium source is heated to a temperature between 950 ℃ and 1150 ℃ in a flowing inert gas atmosphere for 24 hours to 72 hours, and then cooled to room temperature at a speed of not more than 20 ℃/minute to obtain a vanadium dioxide-based single crystal.
The inert gas is a gas that does not react with the starting materials and products. The inert gas is flowing. Which is used to carry away gases generated or volatilized from the raw materials during the reaction and as a carrier gas for the gas phase transport of vanadium dioxide. The inert gas used in common use may be one or more of nitrogen, argon, helium, and the like. Preferably, the inert gas is selected from the group consisting of: nitrogen, argon, and combinations thereof. In the method for producing a vanadium dioxide-based single crystal, the flowing inert gas atmosphere preferably includes convection of an inert gas. Under the environment including convection, the growth of vanadium dioxide crystals is more facilitated. The vanadium dioxide-based single crystal preparation method does not particularly specify the flow rate of the inert gas.
Heating the sample to a temperature of 950-1150 ℃ under a flowing inert gas atmosphere for 24-72 hours, and then cooling to room temperature at a speed of not more than 20 ℃/min to obtain a vanadium dioxide-based single crystal.
The influence of the temperature rise process on the product of the invention is not obvious. Typically, the temperature may be increased at a ramp rate of, for example, 10 deg.C/minute.
The holding temperature and time are critical to the preparation method of the vanadium dioxide-based single crystal. The temperature needs to be between 950 ℃ and 1150 ℃, preferably between 1000 ℃ and 1150 ℃. If the temperature is too low, large-sized high-quality single crystals cannot be formed, or even VO cannot be formed 2A phase. If the temperature is too high, VO2VO at higher temperature and with tendency to generate oxygen vacancies in the material2If the phase is decomposed, a vanadium dioxide-based single crystal cannot be obtained. The incubation time is required to be 24 to 72 hours, preferably 48 to 60 hours. If the time is too short, the single crystal size is small and even only a granular powder is obtained. If the time is too long, the vanadium dioxide-based single crystal is difficult to grow continuously.
And after the heat preservation is finished, cooling to room temperature at the speed of not higher than 20 ℃/min. If the temperature reduction speed is too fast, residual stress is introduced into the vanadium dioxide-based single crystal, so that the quality of the single crystal is reduced. Preferably, the cooling rate is more than 5 ℃/minute so as not to take too long.
In the above manner, a large-sized vanadium dioxide-based single crystal can be formed in a specific temperature range by the synergistic effect of the thermal decomposition of the raw material containing a vanadium source and an optional doping element source and the inert gas flow on the transport of oxygen and vanadium atoms.
Preferably, the source comprising the vanadium source is placed in a semi-open vessel. Placing the raw materials in a semi-open container is beneficial to preventing inert gas flow from blowing away raw material powder and is also beneficial to providing a better microenvironment for single crystal growth. A semi-open container refers to a container having only one opening. A typical example of a semi-open container is a single-opening tube. The gas flows into the container through the opening and flows out through the opening again, and a stable convection atmosphere is formed in the container. The raw material powder is not carried out of the semi-open container by the gas flow and the deposition growth is carried out under the convection gas flow in the container.
When the raw materials are melted at the heating temperature of the process, the melted raw materials are prevented from flowing and spreading in the vessel. For example, when the vessel is a single-port tube and is positioned in a horizontal inert gas flow, if it is positioned horizontally or diagonally downward (the nozzle is below the bottom of the tube), the molten feedstock will tend to spread out and even flow out of the nozzle. A single-opening tube, also referred to herein as a sample tube, is a tube similar to a test tube, having a tube body of uniform thickness and a tube mouth and a tube bottom at both ends, respectively. At this time, the single-opening tube should be placed obliquely so that the opening is higher than the bottom of the tube, thereby collecting the molten raw material at the bottom of the tube. Meanwhile, in order to realize the gas phase convection growth in the reaction system, the inclination angle is not too large, otherwise, inert gas flow is difficult to enter a single-opening tube, only vanadium dioxide-based particles generated by the decomposition of a vanadium source can be obtained, and the growth of large-size single crystals cannot be carried out. Preferably, the angle between the length direction and the horizontal plane is 5 to 35 °. More preferably, the angle between the length direction and the horizontal plane is between 20 ° and 30 °. Preferably, the single-ported tube is positioned with its vertical plane parallel to the direction of the external inert gas flow, with its ports facing substantially in the upstream direction of the external inert gas flow.
The semi-open vessel may be otherwise provided so long as it is satisfied that the raw materials in the semi-open vessel may be in a flowing inert gas atmosphere including convection. When the raw material is melted in the temperature range of the present invention, the inclination angle of the semi-open vessel is set to avoid the melted raw material from spreading or flowing out of the vessel.
Since the vanadium dioxide-based single crystal preparation method is carried out in a flowing inert gas atmosphere and the raw materials are generally in powder form, loading the raw materials in the tube can provide a better semi-enclosed space, better forming convective circulation of gaseous vanadium oxygen species within the space. In addition, the use of a single open tube to hold the material also utilizes the feeding of the material into the heating device and the removal of the product from the heating device. When a single-opening tube is used, the raw material may be put into the tube, and then the tube may be placed in a heating device such as an annealing furnace in which an inert gas flow is horizontally passed, with the tube opening directed obliquely upward.
The sample tube can be a round or square tube. The material of the sample tube can be selected from one or more of quartz glass, corundum and graphite. The inner diameter of the device can be 0.5-2 cm, and the length of the device can be 5-20 cm. Preferably, the material of the sample tube is selected from one or more of quartz glass and corundum, the inner diameter is 0.8-1.2 cm, and the length is 8-12 cm. More preferably, the inner diameter is 0.9-1.1 cm, and the length is 9-11 cm.
In the method for producing a vanadium dioxide-based single crystal, the mass of the vanadium source compound may be 50 to 1000mg, preferably 200 to 600mg, and more preferably 300 to 400mg, from the viewpoint of the size of the single crystal product to be obtained.
When a semi-open container is used to provide the inclined surface, the semi-open container may be placed in an annealing furnace and an inert gas is passed through the annealing furnace. In other words, the whole of the semi-open container is in an external flowing inert gas atmosphere. The opening of the semi-open vessel is preferably directed substantially upstream of the flow of inert gas to the exterior so that the inert gas readily flows into the semi-open vessel and forms a convective atmosphere within the vessel that facilitates the growth of the single crystal of vanadium dioxide. The direction of the external inert gas flow may be inclined or horizontal as long as it can flow into the semi-open container. The direction of the external inert gas flow is preferably horizontal in view of the arrangement of the cavity of a typical heater such as an oven.
The large-size vanadium dioxide-based single crystal can be prepared by the preparation method of the vanadium dioxide-based single crystal. The large-sized vanadium dioxide-based single crystal may be a rod-shaped single crystal having a length of 1 mm or more. The maximum length can be as much as 6 mm or more. The rod-shaped single crystal may have a diameter of several hundred micrometers. Such size and shape facilitates its further fabrication into the desired device.
In particular, the vanadium dioxide-based single crystal has a large negative temperature coefficient near room temperature, high sensitivity and quick response.
The vanadium dioxide-based single crystal has large size and high quality, and is suitable for practical application in high-precision and quick response. The preparation method is simple and cheap, and the flow is simple and easy to operate, so that the method has great application value.
The temperature sensor of the present invention includes:
a resistance measuring device; and
the vanadium dioxide-based single crystal produced by the above method:
wherein the resistance measuring instrument is configured to measure the resistance of the vanadium dioxide-based single crystal.
The resistance measuring device is used for measuring the resistance of the vanadium dioxide-based single crystal. After the corresponding characterization of the temperature-resistance is carried out on the vanadium dioxide-based single crystal in advance, the temperature of the vanadium dioxide-based single crystal can be obtained according to the resistance.
Preferably, the vanadium dioxide-based single crystal used in the temperature sensor is a rod-like single crystal having a length of 1 mm or more and a diameter of 100 μm or more. Such a large-sized single crystal is convenient to install and use, and is excellent in crystallinity, and can provide an accurate response to temperature.
Preferably, the resistance measuring device comprises a voltmeter and an ammeter, and the resistance is calculated by measuring the voltage and the current, wherein two connection points of the ammeter and the vanadium dioxide-based single crystal are between the voltmeter and the two connection points of the vanadium dioxide-based single crystal.
Alternatively, the resistance can be measured directly using a resistance meter, but the results are more accurate using the above-described method using a voltmeter and an ammeter.
The resistance measuring device, such as a voltmeter and an ammeter, or the resistance meter and the vanadium dioxide-based single crystal can be connected in various ways, such as metal welding, conductive silver adhesive, conductive gold adhesive, conductive polymer adhesive and the like. The connecting wire can be selected from conventional metal wires, such as one or more of copper wires, gold wires, silver wires, aluminum wires, iron wires, and the like.
Preferably, the vanadium dioxide-based single crystal is fixed on an insulating substrate. The insulating substrate provides support for the vanadium dioxide-based single crystal probe, and the mechanical stability of the vanadium dioxide-based single crystal probe is improved. The insulating substrate may be selected from, for example, a glass sheet, a plastic sheet, a quartz sheet, an insulating ceramic sheet, and the like.
The vanadium dioxide-based single crystal may be fixed to the insulating substrate by means of an adhesive or the like. The invention is not limited in this regard.
The invention is illustrated by the following more detailed description.
A method for producing a vanadium dioxide-based single crystal according to an embodiment of the present invention includes the steps of:
a) adding vanadium source powder into the sample tube;
the sample tube is a round or square sample tube with a single opening, the material of the sample tube is selected from one or more of quartz glass, corundum and graphite, the inner diameter is 0.5-2 cm, and the length is 5-20 cm; the preferred conditions are: the sample tube is made of one or more of quartz glass and corundum, the inner diameter is 0.8-1.2 cm, and the length is 8-12 cm; more preferred conditions are: the inner diameter is 0.9-1.1 cm, and the length is 9-11 cm.
The vanadium source compound is selected from one or more of vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, vanadyl sulfate hydrate and vanadium sulfate, preferably one or more of vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, vanadyl sulfate hydrate and vanadium sulfate, and more preferably one or more of vanadium pentoxide, ammonium metavanadate and vanadyl oxalate.
The mass of the vanadium source compound is 50-1000 mg, preferably 200-600 mg, and more preferably 300-400 mg.
b) Placing the sample tube in a sample chamber of a tubular annealing furnace with a gas washing device, introducing inert gas to remove oxygen, and then maintaining the inert gas flow at a constant flow rate;
the sample tube is placed in the sample chamber in an inclined mode, the opening faces upwards and faces to the upstream of the airflow, and the tangential angle is 5-35 degrees, and preferably 20-30 degrees.
The sample chamber of the tubular annealing furnace with the gas washing device is selected from one or more of sample chambers with round shapes, square shapes and the like and two open ends.
The tubular annealing furnace sample chamber with the gas washing device is provided with a lining, and the lining is made of one or more materials selected from quartz glass, corundum and graphite; preferably one or more of quartz glass and corundum;
the gas washing process can be realized by vacuumizing and filling inert gas or continuously introducing the inert gas for flushing.
The inert gas is one or more selected from nitrogen, argon and helium; preferably one or more of nitrogen and argon inert gases.
The flow rate is 20 sccm-500 sccm, and the specific preferred value is selected according to the size of the sample chamber.
c) And setting a muffle furnace temperature control program, keeping the temperature of the muffle furnace at a high temperature for a certain time, cooling the muffle furnace, and finally collecting a single crystal sample from the sample tube.
The sample chamber of the tubular annealing furnace with the gas washing device is placed horizontally.
The high temperature is 950 ℃ to 1150 ℃, preferably 1000 ℃ to 1150 ℃.
The certain time is 24 to 72 hours, and preferably 48 to 60 hours.
The cooling rate is not higher than 20 ℃/min.
On the basis, a temperature sensor is prepared:
the sample carrying substrate comprises one or more of insulating type bases such as a glass sheet, a plastic sheet, a quartz sheet, an insulating ceramic sheet and the like. Preferably one or more of an insulating substrate such as a glass sheet, a quartz sheet, or the like.
And connecting a lead to the sample to form the temperature sensor device.
The wires comprise one or more of copper wires, gold wires, silver wires, aluminum wires, iron wires and other metal wires; preferably one or more of copper wires and gold wires.
The connection mode can be realized by various modes such as metal welding, conductive silver adhesive, conductive gold adhesive, conductive polymer adhesive and the like, and two wires or four wires can be connected for resistance measurement; preferably one or more of metal solder, conductive silver paste, etc., using four wires for testing.
While the preferred embodiments of the present invention will now be described in conjunction with the following examples, it is to be understood that these descriptions are merely illustrative of the features and advantages of the present invention, and are not intended to limit the scope of the appended claims. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
adding 300mg of vanadium pentoxide powder into a circular single-opening quartz sample tube with the inner diameter of 1 cm and the length of 10 cm, obliquely placing the circular single-opening quartz sample tube into a horizontal tubular annealing furnace sample chamber with a quartz glass lining and a gas washing device, obliquely placing the sample chamber at an inclination angle of 25 degrees, washing off oxygen and water in the sample chamber by a mode of vacuumizing for three times and filling high-purity nitrogen, keeping the gas flow at 300sccm, and setting a muffle furnace program as follows: rapidly heating to 1000 ℃ at the heating rate of 10 ℃/min, preserving the heat for 60 hours, and then cooling at the cooling rate of 10 ℃/min to obtain the vanadium dioxide single crystal. Fig. 4 shows a schematic view of the arrangement of sample tubes in a muffle furnace.
Fixing a sample on a glass sheet, using copper wires as conducting wires, and arranging four copper wires on a vanadium dioxide single crystal at equal intervals by using soldering tin as a thermosensitive temperature sensor, wherein the schematic diagram is shown in fig. 3.
The resistance temperature relationship between-50 ℃ and 60 ℃ of the thermosensitive temperature sensor is measured on a comprehensive physical property measuring system, and the resistance temperature relationship is shown in figure 1. The resistance temperature characteristics shown in fig. 2 were obtained by data processing, and the B constant of the ntc thermistor was about 3600K.
Example 2:
adding 500mg of ammonium metavanadate powder into a circular single-opening corundum sample tube with the inner diameter of 1.2 cm and the length of 12 cm, obliquely placing the sample tube in a horizontal tubular annealing furnace sample chamber which is lined with quartz glass and is provided with a gas washing device, obliquely placing the sample tube at an inclination angle of 15 degrees, washing off oxygen and water in the sample chamber by a three-time vacuumizing-high-purity argon filling mode, keeping the gas flow at 200sccm, and setting a muffle furnace program as follows: rapidly heating to 1100 ℃ at the heating rate of 10 ℃/min, preserving the heat for 60 hours, and then cooling at the cooling rate of 15 ℃/min. The same identification and detection analyses as in example 1 above were carried out on the obtained sample, and it was confirmed that the obtained sample was a high-quality vanadium dioxide single crystal.
Fixing a sample on a glass sheet, using gold wires as leads, and arranging four gold wires on a vanadium dioxide single crystal at equal intervals by using conductive silver adhesive to serve as thermosensitive temperature sensors.
The resistance-temperature relationship between-50 ℃ and 60 ℃ of the thermosensitive temperature sensor is measured on a comprehensive physical property measuring system. The same identification results as in example 1 were obtained.
Example 3:
adding 300mg of vanadium pentoxide powder into a circular single-opening quartz sample tube with the inner diameter of 1.2 cm and the length of 12 cm, obliquely placing the sample tube into a horizontal tubular annealing furnace sample chamber with a corundum lining and a gas washing device, wherein the inclination angle is 25 degrees, washing off oxygen and water in the sample chamber by a mode of vacuumizing for three times and filling high-purity nitrogen, keeping the gas flow at 300sccm, and setting the muffle furnace program as follows: rapidly heating to 980 ℃ at the heating rate of 8 ℃/min, preserving the heat for 60 hours, and then cooling at the cooling rate of 8 ℃/min. The same identification and detection analyses as in example 1 above were carried out on the samples obtained, confirming that the samples obtained still maintain a high crystalline quality.
Fixing a sample on a quartz plate, using gold wires as conducting wires, and using conductive silver adhesive to arrange four gold wires on a vanadium dioxide single crystal at equal intervals as thermosensitive temperature sensors, wherein the schematic diagram is shown in fig. 3.
The resistance-temperature relationship between-50 ℃ and 60 ℃ of the thermosensitive temperature sensor is measured on a comprehensive physical property measuring system.
The invention provides a thermistor based on a negative temperature coefficient. The negative temperature coefficient thermistor temperature sensor obtained by the invention is based on the proper resistance value and the intrinsic semiconductor characteristic of the vanadium dioxide single crystal in the working temperature range, the resistance of the sample has obvious resistance drop characteristic along with the temperature rise in the working temperature range, and the resistance-temperature relation meets the typical semiconductor law, so that the negative temperature coefficient thermistor temperature sensor has good stability and reproducibility in the temperature rise and fall process. The negative temperature coefficient thermistor obtained by the invention has excellent performance parameters, simple preparation process and low price, is suitable for high-precision temperature detection and temperature compensation within-50 ℃ to 60 ℃, and has great application value in electronic device application.
It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (11)
1. A temperature sensor, the temperature sensor comprising:
a resistance measuring device; and
a vanadium dioxide-based single crystal produced by the steps of:
heating a raw material containing a vanadium source to a temperature of 950 ℃ to 1150 ℃ in a flowing inert gas atmosphere for 24 hours to 72 hours, and then cooling to room temperature at a speed of not more than 20 ℃/minute to obtain a vanadium dioxide-based single crystal, wherein the vanadium source is an oxygen-containing compound containing no other metal element than vanadium, and wherein vanadium has a valence of +4 or +5, and the molar ratio of oxygen to vanadium is 2: 1 or more;
wherein the resistance measuring device is configured for measuring the resistance of the vanadium dioxide based single crystal.
2. The temperature sensor of claim 1,
the source of vanadium is selected from the group consisting of: oxides of vanadium, oxygen-containing vanadium salts, vanadium oxyacid salts, and combinations thereof.
3. The temperature sensor of claim 1,
the source of vanadium is selected from the group consisting of: vanadium pentoxide, ammonium metavanadate, vanadyl oxalate, vanadyl sulfate hydrate, vanadium ammonium sulfate, and combinations thereof.
4. The temperature sensor of claim 1,
The feedstock comprising a source of vanadium is placed in a semi-open vessel.
5. The temperature sensor of claim 1,
the semi-open container is a single-opening pipe which is positioned in a horizontal inert gas flow and is obliquely placed, the pipe orifice of the single-opening pipe is higher than the pipe bottom, and the included angle between the length direction and the horizontal plane is 5-35 degrees.
6. The temperature sensor of claim 1,
the flowing inert gas atmosphere comprises convection of an inert gas.
7. The temperature sensor of claim 1,
the inert gas is selected from the group consisting of: nitrogen, argon, and combinations thereof.
8. The method of claim 1, wherein,
the feedstock also includes a source of a doping element.
9. The temperature sensor of claim 1,
the vanadium dioxide-based single crystal is a rod-like single crystal having a length of 1 mm or more and a diameter of 100 μm or more.
10. The temperature sensor of claim 1,
the resistance measuring device comprises a voltmeter and an ammeter, and the resistance is calculated by measuring voltage and current, wherein two connection points of the voltmeter and the vanadium dioxide-based single crystal are arranged between the ammeter and the two connection points of the vanadium dioxide-based single crystal.
11. The temperature sensor of claim 1,
the vanadium dioxide single crystal is fixed on the insulating substrate.
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| CN201910366138.6A CN111854998A (en) | 2019-04-30 | 2019-04-30 | Temperature sensor |
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| CN201910366138.6A CN111854998A (en) | 2019-04-30 | 2019-04-30 | Temperature sensor |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1095805A (en) * | 1964-06-02 | 1967-12-20 | Matsushita Electric Ind Co Ltd | Method for growing single crystals of vanadium dioxide |
| JPH0658821A (en) * | 1992-08-06 | 1994-03-04 | Nec Corp | Temperature sensor |
| CN101665914A (en) * | 2008-09-02 | 2010-03-10 | 索尼株式会社 | Manufacturing process for one-dimensional nano-structure and apparatus thereof |
| CN103229032A (en) * | 2010-10-04 | 2013-07-31 | 株式会社理光 | Electric element |
| CN105449102A (en) * | 2015-12-04 | 2016-03-30 | 中山大学 | A-phase vanadium dioxide nanowire-based temperature control switch and fabrication method thereof |
| CN109269656A (en) * | 2018-10-19 | 2019-01-25 | 熊锐 | Novel temperature measurement method based on vanadium dioxide gradient film sensor |
-
2019
- 2019-04-30 CN CN201910366138.6A patent/CN111854998A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1095805A (en) * | 1964-06-02 | 1967-12-20 | Matsushita Electric Ind Co Ltd | Method for growing single crystals of vanadium dioxide |
| JPH0658821A (en) * | 1992-08-06 | 1994-03-04 | Nec Corp | Temperature sensor |
| CN101665914A (en) * | 2008-09-02 | 2010-03-10 | 索尼株式会社 | Manufacturing process for one-dimensional nano-structure and apparatus thereof |
| CN103229032A (en) * | 2010-10-04 | 2013-07-31 | 株式会社理光 | Electric element |
| CN105449102A (en) * | 2015-12-04 | 2016-03-30 | 中山大学 | A-phase vanadium dioxide nanowire-based temperature control switch and fabrication method thereof |
| CN109269656A (en) * | 2018-10-19 | 2019-01-25 | 熊锐 | Novel temperature measurement method based on vanadium dioxide gradient film sensor |
Non-Patent Citations (1)
| Title |
|---|
| 杨达莉等: "《大学物理实验教程》", 31 August 2016 * |
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