Applications of high-entropy two-dimensional materials in thermometers and thermometers

Abstract

This invention provides the use of a high-entropy two-dimensional material in a thermometer, wherein the temperature-sensing element of the thermometer is composed of a material having the following chemical formula: HEX 2±δ , 0≤δ≤0.5; wherein, HE is 3-15 metallic elements selected from groups IIIB to VB of the periodic table; the atomic percentage of each metallic element is independently 3%-60% and the sum of the atomic percentages of all metallic elements equals 100%; X is one or more selected from O, S, Se and Te. This invention also provides a thermometer. The thermometer of this invention uses a high-entropy two-dimensional material as the temperature sensing element. The thermometer of this invention has a very wide operating temperature range, for example, it can be used between 0.3K and 420K. Furthermore, the thermometer of this invention features a wide temperature range, high stability, high accuracy, and radiation resistance.

Description

Technical Field

[0001] This invention belongs to the field of materials applications. Specifically, this invention relates to the use of a high-entropy two-dimensional material in a thermometer and the thermometer itself. Background Technology

[0002] One of the most important advances related to cryogenic technology is the development of cryogenic temperature measurement. Cryogenic temperature measurement plays an indispensable role in pharmaceutical storage, laboratory research, industrial cooling systems, practical applications of superconductivity, aerospace, and defense. Over the past two decades, thermometers of various forms and materials have been developed, such as platinum thermometers, semiconductor thermometers (e.g., germanium), rhodium-iron thermometers, carbon glass thermometers, and diode thermometers.

[0003] These thermometers all have certain significant drawbacks. For example, platinum resistance thermometers are very stable in their operating environment, but because the resistance of metals decreases rapidly at low temperatures, the sensitivity of the resistance value to temperature changes also decreases significantly. Therefore, platinum thermometers are generally used for temperature detection above 13K. Semiconductor thermometers, such as those doped with germanium, exhibit non-monotonic resistance changes with temperature above 100K, so their operating temperature is generally below 100K. Rhodium-iron resistance thermometers can cover a temperature range of 0.65K to 400K, but due to the presence of magnetic elements, they exhibit a significant magnetoresistance effect in magnetic fields, thus they cannot be used for temperature detection in strong magnetic fields. Silicon and gallium arsenide diodes can cover the entire temperature range of 1.4K to 500K, but their use in high magnetic fields is limited. Carbon glass resistance thermometers can cover a temperature range of 1.4K to 325K and have good adaptability to magnetic fields, but because carbon glass is prone to crystallization and grain boundary defects between amorphous particles after repeated thermal cycling, its long-term stability is significantly lower than that of platinum, germanium, and rhodium-iron resistance thermometers.

[0004] In many applications, the aforementioned thermometers are insufficient. For example, in high-energy fields, long-term monitoring of superconducting magnets and detection of cryogenic refrigerant liquefaction and distribution are required. Existing thermometers also cannot meet the requirements for monitoring and controlling liquid fuels, propulsion systems, and cooling equipment in aerospace, or the accuracy and stability requirements of thermostats in basic scientific research. Therefore, sensors for these applications need to possess multiple attributes, including a large temperature measurement range from 0.3K (or lower down to dilution cooling temperatures) to 400K, magnetic field insensitivity, radiation hardness, high resolution to detect small temperature changes, fast thermal response time to detect impending magnet quenching, and good long-term stability.

[0005] Given the lack of ideal working materials in the field of cryogenic temperature measurement, in 1989 the U.S. Department of Energy funded a three-phase research project for the development of thermometers for the Superconducting Super Collider. This led to the creation of a ZrN-based thermometer, named Cernox. Cernox thermometers, depending on the grade, can cover a temperature range of 0.1-420K, are less affected by magnetic fields and radiation, and exhibit minimal changes in resistance over long-term use. Therefore, most cryogenic thermometers internationally currently use Cernox thermometers. However, the patent for Cernox is owned by Lake Shore Cryotronics, Inc. (US5367285A), and thermometers used both domestically and internationally must be purchased from this company. Existing Cernox thermometers are expensive and have complex manufacturing processes.

[0006] High-entropy two-dimensional materials have become a research hotspot in recent years, with a focus on their catalytic, magnetic, optical, and superconducting properties. For example, the existing paper "High Entropy van der Waals Materials" (Adv. Sci. 2022, 9, 2203219) discloses their applications in catalysis, magnetism, and optics.

[0007] Therefore, there is an urgent need to develop a new resistance-type, wide-temperature-range, high-precision thermometer with performance comparable to Cernox. Summary of the Invention

[0008] The purpose of this invention is to provide a novel thermometer. This thermometer uses a high-entropy two-dimensional material as its temperature-sensing element. It has a very wide operating temperature range, for example, it can be used between 0.3K and 420K. Furthermore, the thermometer of this invention features a wide temperature range, high stability, high accuracy, and radiation resistance.

[0009] The above-mentioned objective of the present invention is achieved through the following technical solution.

[0010] In the context of this invention, the term "high-entropy two-dimensional material" refers to a two-dimensional material composed of three or more metallic elements selected from groups IIIB to VB of the periodic table.

[0011] On one hand, the present invention provides the use of a high-entropy two-dimensional material in a thermometer, wherein the temperature-sensing element of the thermometer is composed of a material having the following chemical formula:

[0012] HEX 2±δ , 0≤δ≤0.5;

[0013] HE consists of 3-15 metallic elements selected from groups IIIB to VB of the periodic table; the atomic percentage of each metallic element is independently 3%-60% and the sum of the atomic percentages of all metallic elements is equal to 100%.

[0014] X is selected from one or more of O, S, Se and Te.

[0015] The inventors of this invention unexpectedly discovered that when high-entropy two-dimensional materials are used in the temperature sensing element of a thermometer, a thermometer with a wide temperature range, high stability, high accuracy, and radiation resistance can be fabricated. Not wanting to be bound by theory, the concept of this invention is based on the following four points: For a wide monotonic temperature measurement range, the electrical curve of the high-entropy disordered system exhibits range transition behavior, thus ensuring that it does not rapidly diverge in the low-temperature region; for the requirement of magnetic insensitivity, due to the diversity of elemental combinations in the high-entropy system, a material system with small changes in magnetic resistance can be obtained by selecting suitable elements; for cycle life, the high-entropy two-dimensional thin layer is a single crystal, thus effectively reducing the changes caused by weak links between grains and grains during repeated heating and cooling; furthermore, compared with single-component materials, the high-entropy material system has better stability, higher corrosion resistance, and also possesses self-healing properties, exhibiting good tolerance to radiation damage, and is expected to be used in special operating environments such as aerospace and large accelerator beamlines.

[0016] Preferably, in the application of the high-entropy two-dimensional material in a thermometer according to the present invention, the operating temperature range of the thermometer is 0.3K-420K.

[0017] Preferably, in the application of the high-entropy two-dimensional material in a thermometer according to the present invention, the temperature sensing element is composed of the material in the form of a bulk material, a sheet, or a thin film.

[0018] Preferably, in the application of the high-entropy two-dimensional material in a thermometer according to the present invention, the material is a single crystal or a polycrystalline material.

[0019] Preferably, in the use of the high-entropy two-dimensional material of the present invention in a thermometer, the resistance value of the thermometer is from 1 milliohm to 500 megohm.

[0020] On the other hand, the present invention provides a thermometer wherein the temperature-sensing element of the thermometer is composed of a material having the following chemical formula:

[0021] HEX 2±δ , 0≤δ≤0.5;

[0022] HE consists of 3-15 metallic elements selected from groups IIIB to VB of the periodic table; the atomic percentage of each metallic element is independently 3%-60% and the sum of the atomic percentages of all metallic elements is equal to 100%.

[0023] X is selected from one or more of O, S, Se and Te.

[0024] Preferably, in the thermometer described in this invention, the operating temperature range of the thermometer is 0.3K-420K.

[0025] Preferably, in the thermometer of the present invention, the temperature sensing element is made of the material in the form of a block, sheet, or film.

[0026] Preferably, in the thermometer of the present invention, the material is a single crystal or a polycrystalline material.

[0027] Preferably, in the thermometer described in this invention, the resistance value of the thermometer is from 1 milliohm to 500 megohm.

[0028] In a specific embodiment of the present invention, a bulk single-crystal sample of high-entropy two-dimensional material can be obtained by gas-phase transport: First, the selected high-entropy HE element and X element are mixed in a 1:2 ratio (the total atomic percentage of HE element is recorded as 1), the mixture is vacuum-sealed and heated to 600℃~1100℃, held at that temperature for 1 day, and then cooled to obtain HEX. 2-δ Polycrystalline samples; then HEX powder was applied. 2-δ The sample was sealed with a certain amount of elemental iodine, using iodine as the transport medium. The two ends of the quartz tube were placed in tube furnaces at 1000-1100℃ and 800-950℃ respectively for 1-30 days. After cooling to room temperature by quenching, a bulk single crystal of the high-entropy two-dimensional material was obtained.

[0029] In a specific embodiment of the present invention, a high-entropy two-dimensional material thin-film thermometer can be obtained through the following two methods:

[0030] One approach is to use mechanical exfoliation to cleave the obtained bulk single crystal of high-entropy two-dimensional material to the desired thickness using adhesive tape and then attach it to a sapphire substrate. Electrodes are then fabricated using thermal evaporation, magnetron sputtering, or electron beam deposition. Finally, the desired thin-film thermometer is obtained by encapsulation with insulating layers such as boron nitride or electrical sealant.

[0031] Another approach is to directly transport a thin film sample of a certain thickness onto a sapphire substrate using chemical vapor deposition; then, electrodes are prepared by thermal evaporation, magnetron sputtering, or electron beam deposition; finally, a silicon oxide insulating layer or an electrical insulating adhesive is deposited to encapsulate the desired thin film thermometer.

[0032] The present invention has the following beneficial effects:

[0033] This invention provides a high-entropy two-dimensional material, HEX. 2-δ A new application is that it can be used to manufacture thermometers with a wide temperature range, high stability, high precision, and radiation resistance.

[0034] HEX 2-δThe resistance value changes monotonically within the temperature range of 0.3K to 420K, and the resistance value is between 1 milliohm and 500 megohm. Furthermore, HEX... 2-δ The resistance variation range is adjustable with varying composition, thus achieving an optimal temperature sensitivity. The thermometer exhibits a temperature error of less than 1% at 2K after 1000 thermal shocks. Furthermore, the sample shows a magnetoresistance variation of less than 5% under a 9T external field and a resistance variation of less than 2% at 2K after 10kGy γ-ray irradiation, demonstrating excellent radiation resistance. Attached Figure Description

[0035] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein:

[0036] Figure 1 The high-entropy two-dimensional material Ti in Embodiment 1 of this invention 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 Optical photograph of Se2 crystal.

[0037] Figure 2 The high-entropy two-dimensional material Ti in Embodiment 1 of this invention 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 Energy dispersive X-ray spectroscopy (EDX) compositional analysis of Se2 showed proportions close to the nominal stoichiometry.

[0038] Figure 3 The high-entropy two-dimensional material Ti obtained using Example 1 of the present invention 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 Optical photograph of a prototype thin-film resistance thermometer device fabricated with Se2.

[0039] Figure 4 The high-entropy two-dimensional material Ti obtained using Example 1 of the present invention 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 Double logarithmic coordinates of the temperature sensitivity of a prototype thin-film resistance thermometer device fabricated with Se2.

[0040] Figure 5 This refers to the high-entropy two-dimensional material Ti obtained using Example 1 of the present invention. 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15The resistance curves of a prototype thin-film resistance thermometer fabricated by Se2 as a function of temperature, both initially and after 1000 thermal shocks.

[0041] Figure 6 The high-entropy two-dimensional material Ti obtained using Example 1 of the present invention 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 The resistance change of a prototype thin-film resistance thermometer fabricated with Se2 before and after 1000 thermal shocks, divided by the initial resistance value at the corresponding temperature, is shown as a function of temperature.

[0042] Figure 7 The high-entropy two-dimensional material Ti obtained using Example 1 of the present invention 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 The temperature calibration deviation of the prototype thin-film resistance thermometer device prepared by Se2 is obtained by dividing ΔR by d(ΔR) / dT.

[0043] Figure 8 The high-entropy two-dimensional material Ti obtained using Example 2 of the present invention 0.6 V 0.1 Cr 0.1 Nb 0.1 Ta 0.1 Resistance versus temperature curve of a prototype thin-film resistance thermometer device fabricated with Se2

[0044] Figure 9 The high-entropy two-dimensional material Ti obtained using Example 2 of the present invention 0.6 V 0.1 Cr 0.1 Nb 0.1 Ta 0.1 The prototype thin-film resistance thermometer fabricated with Se2 under 9T magnetoresistance effect showed a magnetoresistance value comparable to that of the commercially available Cernox.

[0045] Figure 10 The high-entropy two-dimensional material Ti is from Embodiment 3 of the present invention. 0.2 V 0.2 Cr 0.2 Nb 0.2 Ta 0.2 X-ray diffraction pattern of SSe single crystal.

[0046] Figure 11 The high-entropy two-dimensional material Ti obtained using Example 3 of the present invention 0.2 V 0.2 Cr 0.2 Nb0.2 Ta 0.2 The resistance of the prototype resistance thermometer fabricated by SSe varies with temperature.

[0047] Figure 12 The high-entropy two-dimensional material Ti obtained using Example 3 of the present invention 0.2 V 0.2 Cr 0.2 Nb 0.2 Ta 0.2 The temperature calibration deviation curve of the prototype thin-film resistance thermometer device prepared by SSe after irradiation.

[0048] Figure 13 The high-entropy two-dimensional material Sc obtained using Example 4 of the present invention 0.05 Mo 0.05 W 0.05 Cr 0.05 Ti 0.3 V 0.1 Nb 0.1 Ta 0.1 Zr 0.1 Hf 0.1 The resistance of a prototype resistance thermometer fabricated with Se2 as a function of temperature. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0050] Example 1

[0051] Using Ti 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 High-entropy two-dimensional material Se2 was used to fabricate a prototype resistance thermometer with an operating temperature of 5-400K.

[0052] First, the selected elements were mixed in a ratio of Ti:V:Cr:Nb:Ta:Se = 0.4:0.15:0.15:0.15:0.15:2, and after vacuum sealing, the mixture was heated to 1000℃, held at that temperature for one day, and then cooled to obtain Ti. 0.4 V 0.15 Cr 0.15 Nb 0.15 Ta 0.15 Polycrystalline Se2 sample.

[0053] Subsequently, 1g of powdered Ti 0.4 V 0.15 Cr 0.15 Nb0.15 Ta 0.15 Se2 polycrystalline samples were sealed with 50 mg of elemental iodine, using iodine as the transport medium. The two ends of the quartz tube were placed in tube furnaces at 1050℃ and 950℃ respectively for 20 days. After cooling to room temperature by quenching, a bulk single crystal of the two-dimensional high-entropy material was obtained. An optical photograph of this single crystal is shown below. Figure 1 As shown. Energy-dispersive X-ray spectroscopy (EDX) compositional analysis revealed that the actual composition is close to the nominal proportions, such as... Figure 2 As shown.

[0054] Next, an electrode mask was fabricated on a sapphire glass substrate using a hard mask. Metal electrodes, made of Cr and Au, were deposited on the substrate using thermal evaporation to obtain the required bottom electrode for the device. A high-entropy two-dimensional material single crystal was prepared as a master tape using Scotch tape. A thin sample was peeled from the master tape using polydimethylsiloxane (PDMS) film. A suitable 100 nm thick, flat sheet sample was selected under a metallographic microscope and transferred to the pre-fabricated bottom electrode. The PDMS was slowly lifted to ensure good contact between the sample film and the bottom electrode. Hexagonal boron nitride (h-BN) was used as a protective layer, prepared as a master tape using Scotch tape. This was also peeled using PDMS, and a large-area flat sheet was selected and transferred to the sample surface. This ensured good adhesion of the hexagonal boron nitride to the sample, electrode, and substrate without air bubbles, forming a layer as shown in the image. Figure 3 The device shown.

[0055] The resistance of the prototype device was measured using the standard four-wire method, and the resistance value changed with temperature as follows: Figure 4 As shown. Figure 4 The results show that the resistance of the prototype device changes monotonically with temperature within its operating temperature range. As the temperature decreases, the temperature sensitivity increases, indicating that the prototype device has good temperature resolution at low temperatures.

[0056] To test the prototype device's ability to withstand thermal shock, it was subjected to up to 1000 thermal cycles. The change in resistance with temperature before and after the thermal cycles is shown below. Figure 5 As shown. The ratio of the difference before and after resistance to the original resistance is less than 2% throughout the entire operating temperature range, such as... Figure 6 As shown. The temperature calibration deviation is less than 1K, as... Figure 7 As shown.

[0057] Example 2

[0058] Using Ti 0.6 V 0.1 Cr 0.1 Nb 0.1 Ta 0.1 A prototype resistance thermometer with an operating temperature range of 1.6-400K was fabricated using high-entropy two-dimensional materials of Se2.

[0059] First, the selected elements were mixed in a ratio of Ti:V:Cr:Nb:Ta:Se = 0.6:0.1:0.1:0.1:0.1:2. After vacuum sealing, the mixture was heated to 1000℃, held at that temperature for one day, and then cooled to obtain Ti. 0.6 V 0.1 Cr 0.1 Nb 0.1 Ta 0.1 Polycrystalline Se2 sample.

[0060] Subsequently, 1g of powdered Ti 0.6 V 0.1 Cr 0.1 Nb 0.1 Ta 0.1 Se2 polycrystalline sample and 50 mg of elemental iodine were placed in a tube furnace purged with argon gas, and the temperature of the set region was set to 1050 °C. A sapphire glass substrate was placed at the rear end of the gas flow, and the temperature at the substrate was set to 950 °C. The reaction was carried out for 30 minutes. The sample was then cooled to room temperature by quenching to obtain a thin film of two-dimensional high-entropy material. The fabrication method of the thin film device was the same as in Example 1.

[0061] The resistance of the prototype device was measured using the standard four-wire method, and the resistance value changed with temperature as follows: Figure 8 As shown. Figure 8 This demonstrates that the prototype device has good temperature resolution down to 1.6K.

[0062] To verify the magnetic field stability of the prototype device, a 9T magnetoresistance test was performed on it at 2K, and the results are as follows. Figure 9 As shown, the magnetoresistance is less than 1% at 9T, indicating that the device is suitable for use in strong magnetic field environments such as monitoring the temperature of superconducting magnets.

[0063] Example 3

[0064] Using Ti 0.2 V 0.2 Cr 0.2 Nb 0.2 Ta 0.2 High-entropy two-dimensional SSe materials were used to fabricate prototype resistance thermometers with operating temperatures ranging from 0.3 to 400 K. The single-crystal growth method was the same as in Example 1.

[0065] The high-entropy two-dimensional material Ti prepared in this embodiment 0.2 V 0.2 Cr 0.2 Nb 0.2 Ta 0.2 X-ray diffraction pattern of SSe single crystal as follows Figure 10 As shown. Figure 10The device exhibits sharp diffraction peaks without any impurity peaks, indicating the formation of a single phase and demonstrating that the anion S can be well incorporated into the crystal lattice. The device is constructed from a flat, bulk material, with four silver wires bonded together using silver paste, and encapsulated in high thermal conductivity epoxy resin.

[0066] The resistance of the prototype device was measured using the standard four-wire method, and the resistance value changed with temperature as follows: Figure 11 As shown. Figure 11 This demonstrates that the prototype device has good temperature resolution down to 0.3K.

[0067] To test the radiation resistance of the prototype device, it was irradiated with gamma rays at an intensity of 0.007 Gy / s and a total radiation dose of 10 kGy. The temperature calibration deviation after irradiation is as follows: Figure 12 As shown, the temperature calibration deviation caused by gamma rays is less than 1K. This indicates that the device holds promise for use in demanding environments such as particle accelerators and aerospace.

[0068] Example 4

[0069] Using component Sc 0.05 Mo 0.05 W 0.05 Cr 0.05 Ti 0.3 V 0.1 Nb 0.1 Ta 0.1 Zr 0.1 Hf 0.1 A prototype resistance thermometer with an operating temperature range of 15-400 K was fabricated using high-entropy two-dimensional Se2 materials. The single crystal growth method was the same as in Example 1. The thin film device fabrication method was also the same as in Example 1.

[0070] The resistance of the prototype device was measured using the standard four-wire method, and the resistance value changed with temperature as follows: Figure 13 As shown. Figure 13 This demonstrates that the prototype device has good temperature resolution down to 15K.

Claims

1. Use of a high-entropy two-dimensional material in a thermometer, wherein, The temperature sensor has a temperature sensing element composed of a material with the following chemical formula: HE X HEX 2±δ 0 < δ ≤ 0.5; wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; X is one or more selected from S, Se and Te; The temperature sensor has a temperature sensing element composed of a material with the following chemical formula:

2. Use of the high-entropy two-dimensional material according to claim 1 in a thermometer, wherein, HE X 3. Use of the high-entropy two-dimensional material of claim 2 in a thermometer, wherein, wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; 4. Use of the high-entropy two-dimensional material of claim 1 in a thermometer, wherein, X is one or more selected from S, Se and Te; 5. A thermometer, wherein, The temperature sensor has a temperature sensing element composed of a material with the following chemical formula: HEX 2±δ 0 < δ ≤ 0.5; HE X wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; X is one or more selected from S, Se and Te; 6. The thermometer of claim 5, wherein, The temperature sensor has a temperature sensing element composed of a material with the following chemical formula:

7. The thermometer of claim 6, wherein, HE X 8. The thermometer of claim 5, wherein, wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; X is one or more selected from S, Se and Te; The temperature sensor has a temperature sensing element composed of a material with the following chemical formula: HE X wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; X is one or more selected from S, Se and Te; The temperature sensor has a temperature sensing element composed of a material with the following chemical formula: HE X wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; X is one or more selected from S, Se and Te; The temperature sensor has a temperature sensing element composed of a material with the following chemical formula: HE X wherein HE is 5-10 metal elements selected from the groups IIIB to VB of the periodic table of elements and Cr; the atomic percentage of each metal element is independently 3-60%, and the sum of the atomic percentages of the metal elements is equal to 100%; X is one or more selected from S, Se and Te; The temperature sensor has

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