Preparation method of intermediate valence vanadium oxide electronic phase change material

Abstract

The application provides a mass production method for an intermediate valence state vanadium oxide electronic phase change powder and single crystal, belongs to the field of heat-sensitive electronic phase change materials, and particularly relates to a method for realizing mass production of high-purity and high-uniformity polycrystalline or single crystal materials in a precisely controlled atmosphere by using an additive with the dual effects of fluxing agent and heterogeneous seed crystal, fully dissolving a precursor required for synthesizing the system material by means of a molten alkali halide fluxing agent, and fully reacting the precursor in the process, so as to greatly reduce the reaction temperature and reaction time required for material synthesis, realize mass production of the materials in the precisely controlled atmosphere, and continuously regulate the metal insulator transition temperature of the materials in a wide range by further regulating the valence of vanadium in the intermediate valence state vanadium oxide, the type of doped elements and the doping ratio, so that the method has certain application prospects in the fields of strong light protection, infrared camouflage, thermochromism and sudden change type thermistor devices.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional materials, sensitive resistance materials and devices, and particularly relates to a technical method for effectively preparing intermediate valence vanadium oxide powder, doped vanadium oxide electronic phase change powder and intermediate valence vanadium oxide single crystal with metal insulator phase transition characteristics by using alkali halide as flux and under precisely controlled atmosphere. BACKGROUND

[0002] Among many strong correlation oxide semiconductor material systems with metal insulator phase transition characteristics, intermediate valence vanadium oxide has rich electronic phase structure, wide range of phase transition temperature regulation and high resistivity mutation degree characteristics, and has potential application value in mutation type thermistor, strong correlation logic device, strong light protection, thermochromic, infrared camouflage and the like. The valence of vanadium element in intermediate valence vanadium oxide can be rich between +3 and +5, forming rich binary vanadium oxides such as V2O3, V n O 2n-1 (3≤n≤9) Magnéli phase, VO2, V n O 2n+1 (n≥2) Wadsley phase and the like. Most intermediate valence vanadium oxides have characteristic temperature triggered metal insulator phase transition characteristics, and are accompanied by 3-5 orders of magnitude change in resistivity 【4】. They have rich application prospects in sensitive resistance device and the like.

[0003] The valence of vanadium element in V2O3 is +3, which is transformed from low-temperature insulator phase to high-temperature metal phase at about 168 K, and the resistivity is reduced by 4-5 orders of magnitude 【5】. By doping with metal cations such as Ti 4+ , Cr 3+ , Fe 3+ and the like, the phase transition temperature of V2O3 can be flexibly regulated in the range of 100-200 K 【6】. When doped with metal cations of the same valence, double metal insulator phase transition triggered at different temperatures occurs, i.e. the transition from low-temperature insulator phase to high-temperature metal phase occurs at about 160 K, and the transition from low-temperature metal phase to high-temperature insulator phase occurs at 350-380 K 【7】. By changing the type and concentration of doped metal cations, the phase transition temperature in the high-temperature section can be flexibly regulated in the range of 200-460 K, which has certain application value in positive temperature coefficient thermistor and the like.

[0004] V n O 2n-1 The valence of vanadium element in Magnéli phase (3≤n≤9) is between +3 and +4, except for V7O 13 , the rest of V n O 2n-1All of them undergo a transition from a low-temperature insulator phase to a high-temperature metal phase, with a phase transition temperature spanning 70 K to 430 K and accompanied by a change in resistivity of 1-3 orders of magnitude 【8】. Among them, V n O 2n-1 Among them, V3O5 is the only component known to have a phase transition temperature above room temperature, and the phase transition temperatures of the remaining components are between 70 K and 250 K 【9】. The phase transition temperature can be continuously adjusted in a wide range of 40-450 K by metal cation doping, so this system has considerable application value in the preparation of low-temperature section mutation thermistors.

[0005] V n O 2n+1 The valence of vanadium in the (n≥2) wadsleyite phase is between +4 and +5, and V6O 13 is the only oxide in the wadsleyite phase known to have a metal-insulator transition, which transitions from a low-temperature insulator phase to a high-temperature metal phase at 150 K, accompanied by a 3-4 order of magnitude change in resistivity

[10] . The crystal structure of the wadsleyite vanadium oxide contains VO6 octahedron pipes, which are conducive to the reversible insertion of metal ions and can be used as ion battery electrodes to achieve high energy density and cycle stability

[11] .

[0006] The common method for synthesizing intermediate-valence vanadium oxides at present is solid-phase reaction, which mainly involves using highly toxic V2O3 and V2O5 as raw materials, performing solid-phase reaction multiple times at high temperatures of 800-1000 ℃ under vacuum atmosphere for a long time to synthesize the materials

[12] . In addition, researchers often use chemical vapor transport method, with highly toxic and deliquescent TeCl4, to achieve the preparation of intermediate-valence vanadium oxide single crystals under precise control of high vacuum atmosphere at a specific temperature range of 950-1050 ℃

[13] . It is worth noting that when there is a small deviation in reaction temperature and oxygen pressure, the chemical composition ratio of the final product deviates, resulting in weakening or disappearance of its metal-insulator characteristics. In addition to solid-phase reaction, this system of materials can also be synthesized by chemical method, using VOCl3 as precursor and benzyl alcohol as solvent, and the materials can be synthesized by heating at 250 ℃ for 90 minutes

[14] . However, the electrical and optical properties of intermediate-valence vanadium oxides synthesized by chemical method are difficult to meet the actual use standards.

[0007] In summary, there is currently a lack of an effective method for the synthesis of intermediate-valence vanadium oxides, doped vanadium oxide materials, and intermediate-valence vanadium oxide single crystals in a large amount by one-step reaction at a lower reaction temperature in a shorter time using low-toxicity precursors without the help of reducing atmosphere.

[0008] [1] Ngai J H, Walker F J, Ahn C H. Correlated Oxide Physics and Electronics. Annual Review of Materials Research [J], 2014, 44: 1-17.

[0009] [2] Morin F J. Oxides Which Show a Metal-to-Insulator Transition at the Neel Temperature [J]. Physical Review Letters, 1959, 3(1): 34-6.

[0010] [3] Kachi S, Kosuge K, Okinaka H. Metal-insulator transition in V n O 2n−1 [J]. Journal of Solid State Chemistry, 1973, 6(2): 258-70.

[0011] [4] Nagasawa K, Bando Y, Takada T. Growth and Electrical Properties of V n O 2n−1 (n=3, 4,..., 8) Single Crystals [J]. Bulletin of the Institute for Chemical Research, Kyoto University, 1972, 49(5): 322-41.

[0012] [5] Feinleib J, Paul W. Semiconductor-To-Metal Transition in V2O3 [J]. Physical Review, 1967, 155(3): 841-50.

[0013] [6] McWhan D B, Remeika J P. Metal-Insulator Transition in (V 1-x Cr x)2O3[J]. Physical Review B, 1970, 2(9): 3734-50.

[0014] 【7】 Chandrashekhar G V, Shin S H, Jayaraman A, et al. Electricalproperties of (Ti x V 1–x )2O3 [J]. physica status solidi (a), 1975, 29(1): 323-9.

[0015] 【8】 Kachi S, Kosuge K, Okinaka H. Metal-insulator transition in V n O 2n−1 [J]. Journal of Solid State Chemistry, 1973, 6(2): 258-70.

[0016] 【9】Andreev V N, Klimov V A. Specific features of electricalconductivity of V3O5 single crystals [J]. Physics of the Solid State, 2011, 53(12): 2424-30.

[0017]

[10] Kawashima K, Ueda Y, Kosuge K, et al. Crystal growth and someelectric properties of V6O 13 [J]. Journal of Crystal Growth, 1974, 26(2): 321-2.

[0018]

[11] Shimizu Y, Aoyama S, Jinno T, et al. Site-Selective MottTransition in a Quasi-One-Dimensional Vanadate V6O 13 [J]. Physical Review Letters, 2015, 114(16).

[0019]

[12] MacChesney J B, Guggenheim H J. Growth and electrical properties of vanadium dioxide single crystals containing selected impurity ions [J]. Journal of Physics and Chemistry of Solids, 1969, 30(2): 225-34.

[0020]

[13] Okinaka H, Nagasawa K, Kosuge K, et al. Electrical Properties of the V5O9 Single Crystals [J]. Journal of the Physical Society of Japan, 1970, 28(3): 803.

[0021]

[14] Jing Xu, Chenguo Hu, Huayong Han, Mingquan He, Buyong Wan and Chuanhui Xia, "The synthesis and photoelectric response of single-crystalline V4O7 nanowires," 2010 3rd International Nanoelectronics Conference (INEC), Hong Kong, 2010, pp. 413-414. SUMMARY

[0022] The application aims to provide a preparation method of intermediate valence vanadium oxide electronic phase change ceramic material; the main idea is to use metal vanadium, low-toxicity VO2, V2O5 and NaVO3 powder as precursors, use molten alkali halide flux to fully dissolve the system material precursors, and generate the intermediate valence vanadium oxide to be prepared in a vacuum or inert gas atmosphere during the cooling process, and precipitate together with the gradually solidified alkali halide molten salt. Compared with the previous synthesis method of the system material, the advantages of the technology provided by the application are that the low-toxicity precursors are used, the molten alkali halide flux is used, the synthesis temperature of the material is greatly reduced without relying on the reducing atmosphere, the reaction time is shortened, the valence of vanadium in the intermediate valence vanadium oxide is flexibly controlled, the powder of the material system is prepared in large quantities, and the single crystal of the material system is efficiently grown. By adjusting the proportion of high-valence and low-valence vanadium element precursors and the type and proportion of transition metal oxide dopants, the composition and crystal structure of the prepared intermediate valence vanadium oxide can be accurately controlled, and the wide-range adjustment of the metal insulator phase transition characteristics and the electric transport relationship can be further realized. The prepared material has application value in the fields of positive and negative temperature coefficient jump type thermistors, strong light protection, thermochromic and infrared camouflage, etc.

[0023] A preparation method of intermediate valence vanadium oxide electronic phase change material, characterized in that a synthesis method is provided to grow vanadium oxide material with intermediate valence vanadium element and simultaneously introduce dopant elements; the preparation method can synthesize VO2, magneli phase V n O 2n-1 (3≤n≤9), V2O3, wurtzite phase V n O 2n+1 (3≤n≤9); in combination with the valence control of vanadium element and the doping of transition metal element, the wide-range continuous control of the electronic phase change temperature in the range of 40-450 K can be realized. The method comprises the following steps:

[0024] 1) According to the metal insulator electronic phase change characteristics to be realized, select vanadium element single substance and oxide with higher or lower valence than the target intermediate valence vanadium oxide, such as metal vanadium powder, low-toxicity VO2, V2O5 and NaVO3, and add dopant metal oxide, and determine the amount-of-substance ratio of vanadium-containing precursor and dopant metal oxide according to the principles of element mass conservation and element electron transfer conservation before and after synthesis, weigh and mix thoroughly.

[0025] 2) Add flux with a certain melting point according to the temperature of the subsequent solid phase reaction, and add the selected flux into the above-mentioned precursor mixed powder in a certain proportion, and mix again.

[0026] 3) using a certain atmosphere annealing process, first add alkali halide fluxing agent of the precursor in the oxygen partial pressure for precise control within a certain range of vacuum or inert atmosphere, with a heating rate of 10 ℃ / min rapidly heated to above the melting point of fluxing agent, so that the precursor is fully dissolved in the molten fluxing agent, to ensure the precise control of the valence state of vanadium element in the intermediate valence vanadium oxide; then slowly cooled to below the melting point of fluxing agent, after a period of time, according to the set cooling rate to room temperature; by water washing to remove the alkali halide fluxing agent in the powder product obtained, so as to obtain intermediate valence vanadium oxide powder or single crystal; the obtained powder is further cold pressed and sintered to obtain intermediate valence vanadium oxide ceramic.

[0027] Further, step 1) by regulating the valence state of vanadium element in the intermediate valence vanadium oxide and combining with the substitution of main group metal elements or transition group metal elements to vanadium element, the metal insulator phase transition feature triggering temperature in the range of 40-450 K can be regulated; wherein the valence state of vanadium element can be controlled by metallic vanadium powder, VO2, V2O5 and NaVO3, including the following components: V2O3, V3O5, V4O7, V5O9, V6O 11 , VO2, V6O 13 ; transition group elements mainly include Cr, Ti, Mo, Fe, W, Nb, Zr.

[0028] Further, in the synthesis of V2O3, the transition group doping elements are preferably Cr, Ti, Mo, Fe, Zr, and the main group doping elements are preferably Al, Ga, In; the fluxing agent includes LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single fluxing agent can be used to assist new phase growth, or a plurality of fluxing agents such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl can be used to assist new phase growth; the melting point of the fluxing agent is required to be lower than the melting point required for the synthesis of V2O3, and the fluxing agent can dissolve the precursor powder in a high temperature liquid state, so that the precursor powder is uniformly dispersed in the fluxing agent at high temperature, and the reaction rate is accelerated. The mixture of the precursor and the fluxing agent should be heated to a temperature above the melting point of the fluxing agent at an oxygen partial pressure of 10 -10 -10 -8V2O3 pure phase powder can be obtained in a vacuum or inert atmosphere precisely controlled in the range of Pa, at 800-900 ℃ for 24 hours, and cooled to room temperature at a cooling rate of 2-5 ℃ / min; when the doping metal element is Cr, Al, Ga, In, etc., the doping V2O3 has a metal-insulator phase transition triggered by different characteristic temperatures, i.e., a transition from a low-temperature insulator phase to a high-temperature metal phase occurs near 170 K, and a transition from a low-temperature metal phase to a high-temperature insulator phase occurs near 380 K.

[0029] Further, in the synthesis of the intermediate valence vanadium oxide V3O5 in the Magneli phase, the transition group doping elements are preferably Cr, Ti, Mo, Nb, Fe; the fluxing agents include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single fluxing agent can be used to assist the growth of a new phase, or a plurality of fluxing agents such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl can be used to assist the growth of a new phase; the melting point of the fluxing agent is required to be lower than the melting point required for the synthesis of V3O5, and the precursor powder can be dissolved in the fluxing agent in a high-temperature liquid state, so that the precursor powder is uniformly dispersed in the fluxing agent at high temperature, and the reaction rate is accelerated. The mixture of the precursor and the fluxing agent should be heated to a temperature of 800-1000 ℃ in a vacuum or inert atmosphere with an oxygen partial pressure of 10 -8 -10 -7 V3O5 pure phase powder can be obtained in a vacuum or inert atmosphere precisely controlled in the range of Pa, at 820-920 ℃ for 24 hours, and cooled to room temperature at a cooling rate of 2-5 ℃ / min.

[0030] Further, in the synthesis of the intermediate valence vanadium oxide V4O7 in the Magneli phase, the transition group doping elements are preferably Cr, Ti, Mo, Nb, Fe; the fluxing agents include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single fluxing agent can be used to assist the growth of a new phase, or a plurality of fluxing agents such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl can be used to assist the growth of a new phase; the melting point of the fluxing agent is required to be lower than the melting point required for the synthesis of V4O7, and the precursor powder can be dissolved in the fluxing agent in a high-temperature liquid state, so that the precursor powder is uniformly dispersed in the fluxing agent at high temperature, and the reaction rate is accelerated. The mixture of the precursor and the fluxing agent should be heated to a temperature of 800-1000 ℃ in a vacuum or inert atmosphere with an oxygen partial pressure of 10 -7 -10 -6V4O7 pure phase powder can be obtained by keeping the temperature at 830-930 ℃ for 24 hours in a vacuum or inert atmosphere with accurate control of the pressure in the range of 10

[0031] Further, in the synthesis of intermediate valence vanadium oxide V5O9 in the Magneli phase, the transition group doping elements are preferably Cr, Ti, Mo, Nb, Fe; the fluxing agents include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single fluxing agent can be used to assist the growth of new phases, or a mixture of KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl, etc. can be used to assist the growth of new phases; the melting point of the fluxing agent is required to be lower than the melting point required for the synthesis of V5O9, and the precursor powder can be dissolved in the fluxing agent at high temperature to make the precursor powder uniformly dispersed in the fluxing agent at high temperature, thereby accelerating the reaction rate. The mixture of the precursor and the fluxing agent should be kept at a temperature of 800-1000 ℃ in a vacuum or inert atmosphere with accurate control of the pressure in the range of 10 -6 -10 -5 V5O9 pure phase powder can be obtained by keeping the temperature at 840-940 ℃ for 24 hours in a vacuum or inert atmosphere with accurate control of the pressure in the range of 10

[0032] Further, in the synthesis of intermediate valence vanadium oxide V6O 11 in the Magneli phase, the transition group doping elements are preferably Cr, Ti, Mo, Nb, Fe; the fluxing agents include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single fluxing agent can be used to assist the growth of new phases, or a mixture of KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl, etc. can be used to assist the growth of new phases; the melting point of the fluxing agent is required to be lower than the melting point required for the synthesis of V6O 11 , and the precursor powder can be dissolved in the fluxing agent at high temperature to make the precursor powder uniformly dispersed in the fluxing agent at high temperature, thereby accelerating the reaction rate. The mixture of the precursor and the fluxing agent should be kept at a temperature of 800-1000 ℃ in a vacuum or inert atmosphere with accurate control of the pressure in the range of 10 -5 -10 -4 V6O 11 pure phase powder can be obtained by keeping the temperature at 850-950 ℃ for 24 hours in a vacuum or inert atmosphere with accurate control of the pressure in the range of 10

[0033] Further, in the synthesis of doped VO2, the transition group doping elements are preferably Cr, Ti, Mo, Fe, W, Nb; the fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single flux can be used to assist the growth of new phases, or a plurality of fluxes such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl can be used to assist the growth of new phases; the melting point of the fluxes is required to be lower than the melting point required for the synthesis of doped VO2, and the fluxes can dissolve the precursor powder at high temperature to make the precursor powder uniformly dispersed in the fluxes at high temperature, thereby accelerating the reaction rate. The mixture of the precursor of the material to be synthesized and the fluxes should be in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10 -4 -10 -2 Pa, and is kept at 850-950 ℃ for 24 hours, and is cooled to room temperature at a cooling rate of 2-5 ℃ / min, to obtain a pure phase powder of doped VO2. By adjusting the types and proportions of transition group doping elements, the metal-insulator phase transition temperature of VO2 can be flexibly adjusted in the temperature range of 100-400 K.

[0034] Further, in the synthesis of the intermediate valence vanadium oxide V6O 13 , the transition group doping elements are preferably Cr, Ti, Nb, Mo; the fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single flux can be used to assist the growth of new phases, or a plurality of fluxes such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl can be used to assist the growth of new phases; the melting point of the fluxes is required to be lower than the melting point required for the synthesis of V6O 13 , and the fluxes can dissolve the precursor powder at high temperature to make the precursor powder uniformly dispersed in the fluxes at high temperature, thereby accelerating the reaction rate. The mixture of the precursor of the material to be synthesized and the fluxes should be in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10 -5 -10 -3 Pa, and is kept at 650-750 ℃ for 24 hours, and is cooled to room temperature at a cooling rate of 5 ℃ / min, to obtain a pure phase powder of V6O 13 .

[0035] Further, in the synthesis of the intermediate-valence vanadium oxide, by controlling the cooling rate, the grain size of the material can be flexibly controlled; if the cooling rate is 0.01-1 ℃ / min, the intermediate-valence vanadium oxide single crystal grown in a specific crystal direction can be synthesized by slowly cooling from a certain reaction temperature to room temperature, and the grain size is 1-5 mm; if the cooling rate is 2-5 ℃ / min, the intermediate-valence vanadium oxide powder can be synthesized by slowly cooling from a certain reaction temperature to room temperature, and the grain size is 30-50 μm; if water is used as a coolant, the intermediate-valence vanadium oxide powder can be obtained by rapidly cooling from a certain reaction temperature to room temperature through quenching, and the grain size is 5-10 μm.

[0036] The present application provides a mass production method of intermediate-valence vanadium oxide electronic phase change powder, ceramic material and single crystal. Compared with other methods, the method has the advantages that by means of the molten alkali metal halide flux, the precursor required for synthesizing the system material is fully dissolved, the precursor is fully reacted in the process, the reaction temperature and reaction time required for synthesizing the material are greatly reduced, the mass production of the material in a polycrystalline or single crystal form with high purity and high uniformity under a precisely controlled atmosphere can be realized, by further adjusting the valence of vanadium element, the type and doping ratio of the doping element in the intermediate-valence vanadium oxide compound, the metal-insulator transition temperature of the material can be continuously adjusted in a wide range, and the method has certain application prospects in the fields of strong light protection, infrared camouflage, thermochromic and sudden change type thermistor devices. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The X-ray diffraction pattern of the V2O3 powder prepared by the flux method provided by the present application can be seen that the prepared powder is a pure phase powder.

[0038] Figure 2 The X-ray diffraction pattern of the (V 0.99 Cr 0.01 )2O3 powder material prepared by the flux method provided by the present application can be seen that the prepared powder is a pure phase powder.

[0039] Figure 3 The relationship diagram of the resistivity of the (V 0.99 Cr 0.01 )2O3 powder material prepared by the flux method provided by the present application with temperature. The material has two metal-insulator phase transitions, a low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition temperature 168 K; a low-temperature metal phase to high-temperature insulator phase transition occurs near the phase transition temperature 400 K.

[0040] Figure 4The X-ray diffraction pattern of the V2O3 powder prepared by the flux method according to the present application shows that the prepared powder is a pure phase powder.

[0041] Figure 5 The temperature dependence of the resistivity of the V2O3 powder material prepared by the flux method according to the present application. The material undergoes a low-temperature insulator phase to high-temperature metal phase transition near the phase transition temperature of 168 K. DETAILED DESCRIPTION

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Methods and materials similar or equivalent to those described herein can be used in the practice of the present application. Unless otherwise indicated, all technical and scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art.

[0043] Additional aspects of the application will be apparent to those of ordinary skill in the art in view of the foregoing description.

[0044] The application is further described in the following examples. It is to be understood that these examples are merely illustrative of specific embodiments of the application and do not limit the scope of the application. Unless otherwise noted, the experimental methods in the following examples were carried out according to conventional procedures or as recommended by the manufacturer.

[0045] Example 1: V and V02 were weighed according to the elemental molar ratio of V:V02 = 1.5:0.5, and then were put into an agate mortar and ground thoroughly. KCl was weighed according to the molar ratio of V02:KCl = 1:10, and then was added to the mixed and uniformly ground V02 and metal V powder. The mixture was again ground thoroughly, and then was cold-pressed into a 10 mm diameter block using a press. The block was then placed in an alumina crucible, and was sintered at 900 °C for 30 minutes in a vacuum or inert atmosphere with an oxygen partial pressure of 10 Pa, and then was kept at 800 °C for 24 hours. After the reaction, the block was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain a pure phase V205 powder. The ceramic material of this component was obtained by adding a binder to the obtained powder and cold-pressing and sintering. The material undergoes a low-temperature insulator phase to high-temperature metal phase transition near the phase transition temperature of 428 K, and the triggered resistivity mutation degree is 100 times. -10 -10 -8 Pa range, was first sintered at 900 °C for 30 minutes, and then was kept at 800 °C for 24 hours. After the reaction, the block was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain a pure phase V203 powder. The ceramic material of this component was obtained by adding a binder to the obtained powder and cold-pressing and sintering. The material undergoes a low-temperature insulator phase to high-temperature metal phase transition near the phase transition temperature of 168 K, and the triggered resistivity mutation degree is 100 times.

[0046] Example 2: V, VO2, Cr2O3 are weighed according to the elemental molar ratio V:VO2:Cr2O3=1.485:0.495:0.01, and are placed in an agate mortar and ground thoroughly and uniformly. Then KCl is weighed according to the molar ratio VO2:KCl=1:10, and is added to the uniformly mixed VO2 and metal V powder, which is again ground thoroughly and uniformly. The mixture is cold-pressed into a 10 mm diameter block using a press, and is then placed in an alumina crucible. The sintering is carried out in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10-10 Pa, first at 900°C for 30 minutes, and then at 800°C for 24 hours. After the reaction is complete, the temperature is cooled to room temperature at a rate of 5°C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase (V -10 -10 -8 )2O3 powder. A binder is added to the obtained powder, which is cold-pressed and sintered to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, triggering a 100-fold change in resistivity. A low-temperature metal phase to high-temperature insulator phase transition occurs near 400 K, triggering a 3-fold change in resistivity. 0.99 Cr 0.01 )2O3 powder, a binder is added to the obtained powder, which is cold-pressed and sintered to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, triggering a 100-fold change in resistivity. A low-temperature metal phase to high-temperature insulator phase transition occurs near 400 K, triggering a 3-fold change in resistivity.

[0047] Example 3: V, VO2, In2O3 are weighed according to the elemental molar ratio V:VO2:In2O3=1.485:0.495:0.01, and are placed in an agate mortar and ground thoroughly and uniformly. Then KCl is weighed according to the molar ratio VO2:KCl=1:10, and is added to the uniformly mixed VO2 and metal V powder, which is again ground thoroughly and uniformly. The mixture is cold-pressed into a 10 mm diameter block using a press, and is then placed in an alumina crucible. The sintering is carried out in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10-10 Pa, first at 900°C for 30 minutes, and then at 800°C for 24 hours. After the reaction is complete, the temperature is cooled to room temperature at a rate of 5°C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase (V -10 -10 -8 )2O3 powder. A binder is added to the obtained powder, which is cold-pressed and sintered to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, triggering a 100-fold change in resistivity. A low-temperature metal phase to high-temperature insulator phase transition occurs near 400 K, triggering a 3-fold change in resistivity. 0.99 In 0.01 )2O3 powder, a binder is added to the obtained powder, which is cold-pressed and sintered to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, triggering a 100-fold change in resistivity. A low-temperature metal phase to high-temperature insulator phase transition occurs near 400 K, triggering a 3-fold change in resistivity.

[0048] Example 4: Take V, V02 according to the elemental molar ratio V:V02 = 1.5:0.5, put them in an agate mortar and grind them well, then take NaCl with a molar ratio of V02:NaCl = 1:10, add the well-mixed V02 and metal V powder, grind them well again, cold-press them into a 10 mm diameter block using a press, then put them in an alumina crucible, first sinter at 950 °C for 30 minutes, then keep the temperature at 850 °C for 24 hours, cool to room temperature at a rate of 5 °C / min after the reaction is complete. Finally, rinse the powder sample with deionized water and dry it to obtain pure phase V203 powder. Add a binder to the obtained powder, cold-press it, and then sinter it to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times. -10 -10 -8 Pa range, first sinter at 950 °C for 30 minutes, then keep the temperature at 850 °C for 24 hours, cool to room temperature at a rate of 5 °C / min after the reaction is complete. Finally, rinse the powder sample with deionized water and dry it to obtain pure phase V203 powder. Add a binder to the obtained powder, cold-press it, and then sinter it to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times.

[0049] Example 5: Take V, V205 according to the elemental molar ratio V:V205 = 4:3, put them in an agate mortar and grind them well, then take NaCl with a molar ratio of V205:NaCl = 1:10, add the well-mixed V02 and V205 powder, grind them well again, cold-press them into a 10 mm diameter block using a press, then put them in an alumina crucible, first sinter at 950 °C for 30 minutes, then keep the temperature at 850 °C for 24 hours, cool to room temperature at a rate of 5 °C / min after the reaction is complete. Finally, rinse the powder sample with deionized water and dry it to obtain pure phase V203 powder. Add a binder to the obtained powder, cold-press it, and then sinter it to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times. -10 -10 -8 Pa range, first sinter at 950 °C for 30 minutes, then keep the temperature at 850 °C for 24 hours, cool to room temperature at a rate of 5 °C / min after the reaction is complete. Finally, rinse the powder sample with deionized water and dry it to obtain pure phase V203 powder. Add a binder to the obtained powder, cold-press it, and then sinter it to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times.

[0050] Example 6: Take V, V02 according to the elemental molar ratio V:V02 = 1.5:0.5, put them in an agate mortar and grind them well, then take NaCl and KCl with a molar ratio of V02:NaCl:KCl = 1:10:10, add the well-mixed V02 and metal V powder, grind them well again, cold-press them into a 10 mm diameter block using a press, then put them in an alumina crucible, first sinter at 950 °C for 30 minutes, then keep the temperature at 850 °C for 24 hours, cool to room temperature at a rate of 5 °C / min after the reaction is complete. Finally, rinse the powder sample with deionized water and dry it to obtain pure phase V203 powder. Add a binder to the obtained powder, cold-press it, and then sinter it to obtain the ceramic material of this component. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times. -10 -10 -8The powders were first sintered at 800 °C for 30 min, and then annealed at 700 °C for 24 h in a precisely controlled vacuum or inert atmosphere in the range of 10~3~10~5Pa. After the reaction, the powders were cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples were washed with deionized water and dried to obtain pure-phase V2O3 powder. The ceramic material of this composition was obtained by sintering after adding a binder and cold-pressing. The low-temperature insulator phase to high-temperature metal phase transition occurred near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree was 100 times.

[0051] Example 7: V and VO2 were weighed according to the elemental molar ratio V:VO2=1.5:0.5, and were placed in a agate mortar for grinding. Then, CsI was weighed according to the molar ratio VO2:CsI=1:10, and was added to the uniformly mixed VO2 and metal V powder. The mixture was again uniformly ground, and was cold-pressed into a block with a diameter of 10 mm using a press. Then, the block was placed in an alumina crucible, and was sintered at 650 °C for 30 min, and then annealed at 600 °C for 24 h in a precisely controlled vacuum or inert atmosphere in the range of 10~3~10~5Pa. After the reaction, the powders were cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples were washed with deionized water and dried to obtain pure-phase V2O3 powder. The ceramic material of this composition was obtained by sintering after adding a binder and cold-pressing. The low-temperature insulator phase to high-temperature metal phase transition occurred near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree was 100 times. -10 -10 -8 The powders were first sintered at 800 °C for 30 min, and then annealed at 700 °C for 24 h in a precisely controlled vacuum or inert atmosphere in the range of 10~3~10~5Pa. After the reaction, the powders were cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples were washed with deionized water and dried to obtain pure-phase V2O3 powder. The ceramic material of this composition was obtained by sintering after adding a binder and cold-pressing. The low-temperature insulator phase to high-temperature metal phase transition occurred near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree was 100 times.

[0052] Example 8: V and VO2 were weighed according to the elemental molar ratio V:VO2=1.5:0.5, and were placed in a agate mortar for grinding. Then, KI and RbI were weighed according to the molar ratio VO2:KI:RbI=1:2:1, and were added to the uniformly mixed VO2 and metal V powder. The mixture was again uniformly ground, and was cold-pressed into a block with a diameter of 10 mm using a press. Then, the block was placed in an alumina crucible, and was sintered at 650 °C for 30 min, and then annealed at 600 °C for 24 h in a precisely controlled vacuum or inert atmosphere in the range of 10~3~10~5Pa. After the reaction, the powders were cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples were washed with deionized water and dried to obtain pure-phase V2O3 powder. The ceramic material of this composition was obtained by sintering after adding a binder and cold-pressing. The low-temperature insulator phase to high-temperature metal phase transition occurred near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree was 100 times. -10 -10 -8 The powders were first sintered at 800 °C for 30 min, and then annealed at 700 °C for 24 h in a precisely controlled vacuum or inert atmosphere in the range of 10~3~10~5Pa. After the reaction, the powders were cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples were washed with deionized water and dried to obtain pure-phase V2O3 powder. The ceramic material of this composition was obtained by sintering after adding a binder and cold-pressing. The low-temperature insulator phase to high-temperature metal phase transition occurred near the phase transition characteristic temperature of 168 K, and the triggered resistivity mutation degree was 100 times.

[0053] Example 9: V, VO2 are weighed according to the elemental molar ratio V:VO2 = 2.5:0.5, and are placed in a agate mortar and ground thoroughly. Then KCl is weighed according to the molar ratio VO2:KCl = 1:10, and is added to the well-mixed VO2 and metallic V powder. The mixture is ground again thoroughly, and is cold-pressed into a 10 mm diameter pellet using a press. The pellet is then placed in an alumina crucible, and is sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure of 10-20 Pa. After the reaction is complete, the pellet is cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure-phase V3O5 powder. A ceramic material of this composition is obtained by adding a binder to the powder and cold-pressing and sintering. A low-temperature insulator-to-high-temperature metal phase transition occurs near the characteristic temperature 420 K, and the triggered resistivity mutation degree is 10 times. -8 -10 -7 Pa range, and is first sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours. After the reaction is complete, the pellet is cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure-phase V4O7 powder. A ceramic material of this composition is obtained by adding a binder to the powder and cold-pressing and sintering. A low-temperature insulator-to-high-temperature metal phase transition occurs near the characteristic temperature 250 K, and the triggered resistivity mutation degree is 100 times.

[0054] Example 10: V, VO2 are weighed according to the elemental molar ratio V:VO2 = 3.5:0.5, and are placed in a agate mortar and ground thoroughly. Then KCl is weighed according to the molar ratio VO2:KCl = 1:10, and is added to the well-mixed VO2 and metallic V powder. The mixture is ground again thoroughly, and is cold-pressed into a 10 mm diameter pellet using a press. The pellet is then placed in an alumina crucible, and is sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure of 10-20 Pa. After the reaction is complete, the pellet is cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure-phase V4O7 powder. A ceramic material of this composition is obtained by adding a binder to the powder and cold-pressing and sintering. A low-temperature insulator-to-high-temperature metal phase transition occurs near the characteristic temperature 250 K, and the triggered resistivity mutation degree is 100 times. -7 -10 -6 Pa range, and is first sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours. After the reaction is complete, the pellet is cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure-phase V4O7 powder. A ceramic material of this composition is obtained by adding a binder to the powder and cold-pressing and sintering. A low-temperature insulator-to-high-temperature metal phase transition occurs near the characteristic temperature 250 K, and the triggered resistivity mutation degree is 100 times.

[0055] Example 11: V, VO2 are weighed according to the elemental molar ratio V:VO2 = 4.5:0.5, and are placed in a agate mortar and ground thoroughly. Then KCl is weighed according to the molar ratio VO2:KCl = 1:10, and is added to the well-mixed VO2 and metallic V powder. The mixture is ground again thoroughly, and is cold-pressed into a 10 mm diameter pellet using a press. The pellet is then placed in an alumina crucible, and is sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure of 10-20 Pa. After the reaction is complete, the pellet is cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample is rinsed with deionized water and dried to obtain pure-phase V4O7 powder. A ceramic material of this composition is obtained by adding a binder to the powder and cold-pressing and sintering. A low-temperature insulator-to-high-temperature metal phase transition occurs near the characteristic temperature 250 K, and the triggered resistivity mutation degree is 100 times. -6 -10 -5The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V5O9 powder. The obtained powder was added with a binder, cold-pressed and sintered to obtain a ceramic material of the component, which has a low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 130 K, and the triggered resistivity mutation degree is 200 times.

[0056] Example 12: V and VO2 were weighed according to the element molar ratio V:VO2=5.5:0.5, and were placed in an agate mortar for grinding. Then KCl was weighed according to the molar ratio VO2:KCl=1:10, and was added to the uniformly mixed V and VO2 powders. The mixture was again uniformly ground, and was cold-pressed into a block with a diameter of 10 mm by using a press. Then the block was placed in an alumina crucible, and was sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V6O11 powder. The obtained powder was added with a binder, cold-pressed and sintered to obtain a ceramic material of the component, which has a low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 170 K, and the triggered resistivity mutation degree is 10 times. -5 -10 -4 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V5O9 powder. The obtained powder was added with a binder, cold-pressed and sintered to obtain a ceramic material of the component, which has a low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 130 K, and the triggered resistivity mutation degree is 200 times. 11 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V5O9 powder. The obtained powder was added with a binder, cold-pressed and sintered to obtain a ceramic material of the component, which has a low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 130 K, and the triggered resistivity mutation degree is 200 times.

[0057] Example 13: VO2 and TiO2 were weighed according to the element molar ratio VO2:TiO2=0.95:0.05, and were placed in an agate mortar for grinding. Then KCl was weighed according to the molar ratio VO2:KCl=1:10, and was added to the uniformly mixed VO2 and TiO2 powders. The mixture was again uniformly ground, and was cold-pressed into a block with a diameter of 10 mm by using a press. Then the block was placed in an alumina crucible, and was sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V -4 -10 -3 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V 0.95 Ti 0.05 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 ℃ for 30 minutes, then at 800 ℃ for 24 hours, and after the reaction was completed, the temperature was cooled to room temperature at a rate of 5 ℃ / min. Finally, the powder sample was washed with deionized water and dried to obtain pure phase V5O9 powder. The obtained powder was added with a binder, cold-pressed and sintered to obtain a ceramic material of the component, which has a low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 130 K, and the triggered resistivity mutation degree is 200 times.

[0058] Example 14: VO2 and Cr2O3 were weighed in the elemental molar ratio VO2:Cr2O3 = 0.95:0.05, and were placed in an agate mortar and ground thoroughly to homogeneity. KCl was then weighed in the molar ratio VO2:KCl = 1:10, and was added to the homogeneously mixed VO2 and Cr2O3 powders, which were again ground thoroughly to homogeneity. The mixture was cold-pressed into a 10-mm-diameter pellet using a press, and was then placed in an alumina crucible. The pellet was sintered at 900 °C for 30 min, and then at 800 °C for 24 h in a vacuum or inert atmosphere with an oxygen partial pressure accurately controlled in the range of 10-10to 10-20Pa. After the reaction was completed, the pellet was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure-phase VO2 powder. A ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times. -4 -10 -3 Pa range, first sintered at 900 °C for 30 min, and then at 800 °C for 24 h. After the reaction was completed, the pellet was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure-phase VO2 powder. A ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times. 0.9 Cr 0.1 O2 powder, and a ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times.

[0059] Example 15: VO2 and WO3 were weighed in the elemental molar ratio VO2:WO3 = 0.99:0.01, and were placed in an agate mortar and ground thoroughly to homogeneity. KCl was then weighed in the molar ratio VO2:KCl = 1:10, and was added to the homogeneously mixed VO2 and WO3 powders, which were again ground thoroughly to homogeneity. The mixture was cold-pressed into a 10-mm-diameter pellet using a press, and was then placed in an alumina crucible. The pellet was sintered at 900 °C for 30 min, and then at 800 °C for 24 h in a vacuum or inert atmosphere with an oxygen partial pressure accurately controlled in the range of 10-10to 10-20Pa. After the reaction was completed, the pellet was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure-phase VO2 powder. A ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 300 K, and the triggered resistivity mutation degree is 10 times. -4 -10 -3 Pa range, first sintered at 900 °C for 30 min, and then at 800 °C for 24 h. After the reaction was completed, the pellet was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure-phase VO2 powder. A ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times. 0.99 W 0.01 O2 powder, and a ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times.

[0060] Example 16: VO2 and Nb2O5 were weighed in the elemental molar ratio VO2:Nb2O5 = 0.95:0.05, and were placed in an agate mortar and ground thoroughly to homogeneity. KCl was then weighed in the molar ratio VO2:KCl = 1:10, and was added to the homogeneously mixed VO2 and Nb2O5 powders, which were again ground thoroughly to homogeneity. The mixture was cold-pressed into a 10-mm-diameter pellet using a press, and was then placed in an alumina crucible. The pellet was sintered at 900 °C for 30 min, and then at 800 °C for 24 h in a vacuum or inert atmosphere with an oxygen partial pressure accurately controlled in the range of 10-10to 10-20Pa. After the reaction was completed, the pellet was cooled to room temperature at a rate of 5 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure-phase VO2 powder. A ceramic material of this composition was obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator-to-high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times. -4 -10 -3The powders obtained are sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder. 0.9 Nb 0.1 The powders obtained are sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder.

[0061] Example 17: V and V2O5are weighed according to the elemental molar ratio V2O5:V = 26:4, and are placed in a marver mortar for thorough grinding. Then KCl is weighed according to the molar ratio V2O5:KCl = 1:10, and is added to the uniformly mixed V2O5and V powders. The mixture is again thoroughly ground, and is cold-pressed into a 10 mm diameter block using a press. The block is then placed in an alumina crucible, and is sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder. -5 -10 -3 The powders obtained are sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder. 13 The powders obtained are sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder.

[0062] Example 18: VO2and V2O5are weighed according to the elemental molar ratio V2O5:VO2= 1:4, and are placed in a marver mortar for thorough grinding. Then KCl is weighed according to the molar ratio VO2:KCl = 1:10, and is added to the uniformly mixed V2O5and VO2powders. The mixture is again thoroughly ground, and is cold-pressed into a 10 mm diameter block using a press. The block is then placed in an alumina crucible, and is sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder. -5 -10 -3 The powders obtained are sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder. 13 The powders obtained are sintered in a vacuum or inert atmosphere with precise control of the partial pressure of oxygen in the range of 10-6Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after which the reaction is cooled to room temperature at a rate of 5 °C / min. Finally, the powder samples are rinsed with deionized water and dried to obtain pure phase V6O11powder.

[0063] Example 19: VO2, V2O5, were weighed according to the elemental molar ratio V2O5:VO2 = 1:4, and were placed in a marver mortar for grinding until homogeneity. Then, NaCl and KCl were weighed according to the molar ratio VO2:NaCl:KCl = 1:10:10, and were added to the homogenously mixed V2O5and VO2powders. The mixture was again ground until homogeneity, and was cold-pressed into a 10 mm diameter pellet using a press. The pellet was then placed in an alumina crucible, and was sintered at 800 °C for 30 minutes, and then at 700 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10Pa. After the reaction was complete, the pellet was cooled to room temperature at a rate of 5 °C / min. Finally, the pellet was rinsed with deionized water and dried to obtain a pure phase V6O13ceramic material. The material undergoes a low-temperature insulator to high-temperature metal phase transition near the characteristic phase transition temperature of 150 K, with a triggered resistivity change of 100 times. -5 -10 -3 Pa. After the reaction was complete, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the pellet was rinsed with deionized water and dried to obtain a pure phase V2O3single crystal with a size of about 2 mm. The material undergoes a low-temperature insulator to high-temperature metal phase transition near the characteristic phase transition temperature of 168 K, with a triggered resistivity change of 10,000 times. 13 Pa. After the reaction was complete, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the pellet was rinsed with deionized water and dried to obtain a pure phase V2O3single crystal with a size of about 2 mm. The material undergoes a low-temperature insulator to high-temperature metal phase transition near the characteristic phase transition temperature of 168 K, with a triggered resistivity change of 10,000 times.

[0064] Example 20: V, VO2, were weighed according to the elemental molar ratio V:VO2 = 1.5:0.5, and were placed in a marver mortar for grinding until homogeneity. Then, KCl was weighed according to the molar ratio VO2:KCl = 1:10, and was added to the homogenously mixed V and VO2powders. The mixture was again ground until homogeneity, and was cold-pressed into a 10 mm diameter pellet using a press. The pellet was then placed in an alumina crucible, and was sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10Pa. After the reaction was complete, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the pellet was rinsed with deionized water and dried to obtain a pure phase V2O3single crystal with a size of about 2 mm. The material undergoes a low-temperature insulator to high-temperature metal phase transition near the characteristic phase transition temperature of 168 K, with a triggered resistivity change of 10,000 times. -10 -10 -8 Pa. After the reaction was complete, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the pellet was rinsed with deionized water and dried to obtain a pure phase V2O3single crystal with a size of about 2 mm. The material undergoes a low-temperature insulator to high-temperature metal phase transition near the characteristic phase transition temperature of 168 K, with a triggered resistivity change of 10,000 times.

[0065] Example 21: V, VO2, were weighed according to the elemental molar ratio V:VO2 = 2.5:0.5, and were placed in a marver mortar for grinding until homogeneity. Then, KCl was weighed according to the molar ratio VO2:KCl = 1:10, and was added to the homogenously mixed V and VO2powders. The mixture was again ground until homogeneity, and was cold-pressed into a 10 mm diameter pellet using a press. The pellet was then placed in an alumina crucible, and was sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10Pa. After the reaction was complete, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the pellet was rinsed with deionized water and dried to obtain a pure phase V2O3single crystal with a size of about 2 mm. The material undergoes a low-temperature insulator to high-temperature metal phase transition near the characteristic phase transition temperature of 168 K, with a triggered resistivity change of 10,000 times. -8 -10 -7The V2O3 single crystal with a size of about 2.5 mm is obtained by sintering at 900 ℃ for 30 min and then keeping at 800 ℃ for 24 h in a vacuum or inert atmosphere with a precise control of the pressure in the range of 10~3~10~5Pa, and then cooling to room temperature at a rate of 0.1 ℃ / min. Finally, the powder sample is washed with deionized water and dried to obtain the pure-phase V2O3 single crystal with a size of about 2.5 mm, which has a low-temperature insulator phase to high-temperature metal phase transition near the characteristic temperature of 260 K, and the triggered resistivity mutation degree is 1000 times.

[0066] In example 22, V and VO2 are weighed according to the element molar ratio V:VO2=3.5:0.5, and then put into a agate mortar for grinding, and then KCl is weighed according to the molar ratio of VO2:KCl=1:10, and then added into the mixed VO2 and metal V powder, and then ground again, and then cold-pressed into a block with a diameter of 10 mm by using a press, and then put into an alumina crucible, and then sintered at 900 ℃ for 30 min and then kept at 800 ℃ for 24 h in a vacuum or inert atmosphere with a precise control of the pressure in the range of 10~3~10~5Pa, and then cooled to room temperature at a rate of 0.1 ℃ / min. Finally, the powder sample is washed with deionized water and dried to obtain the pure-phase V2O3 single crystal with a size of about 2.5 mm, which has a low-temperature insulator phase to high-temperature metal phase transition near the characteristic temperature of 260 K, and the triggered resistivity mutation degree is 1000 times. -7 -10 -6 In example 22, V and VO2 are weighed according to the element molar ratio V:VO2=3.5:0.5, and then put into a agate mortar for grinding, and then KCl is weighed according to the molar ratio of VO2:KCl=1:10, and then added into the mixed VO2 and metal V powder, and then ground again, and then cold-pressed into a block with a diameter of 10 mm by using a press, and then put into an alumina crucible, and then sintered at 900 ℃ for 30 min and then kept at 800 ℃ for 24 h in a vacuum or inert atmosphere with a precise control of the pressure in the range of 10~3~10~5Pa, and then cooled to room temperature at a rate of 0.1 ℃ / min. Finally, the powder sample is washed with deionized water and dried to obtain the pure-phase V2O3 single crystal with a size of about 2.5 mm, which has a low-temperature insulator phase to high-temperature metal phase transition near the characteristic temperature of 260 K, and the triggered resistivity mutation degree is 1000 times.

[0067] In example 23, V and VO2 are weighed according to the element molar ratio V:VO2=4.5:0.5, and then put into a agate mortar for grinding, and then KCl is weighed according to the molar ratio of VO2:KCl=1:10, and then added into the mixed VO2 and metal V powder, and then ground again, and then cold-pressed into a block with a diameter of 10 mm by using a press, and then put into an alumina crucible, and then sintered at 900 ℃ for 30 min and then kept at 800 ℃ for 24 h in a vacuum or inert atmosphere with a precise control of the pressure in the range of 10~3~10~5Pa, and then cooled to room temperature at a rate of 0.1 ℃ / min. Finally, the powder sample is washed with deionized water and dried to obtain the pure-phase V2O3 single crystal with a size of about 2.5 mm, which has a low-temperature insulator phase to high-temperature metal phase transition near the characteristic temperature of 260 K, and the triggered resistivity mutation degree is 1000 times. -6 -10 -5 In example 22, V and VO2 are weighed according to the element molar ratio V:VO2=3.5:0.5, and then put into a agate mortar for grinding, and then KCl is weighed according to the molar ratio of VO2:KCl=1:10, and then added into the mixed VO2 and metal V powder, and then ground again, and then cold-pressed into a block with a diameter of 10 mm by using a press, and then put into an alumina crucible, and then sintered at 900 ℃ for 30 min and then kept at 800 ℃ for 24 h in a vacuum or inert atmosphere with a precise control of the pressure in the range of 10~3~10~5Pa, and then cooled to room temperature at a rate of 0.1 ℃ / min. Finally, the powder sample is washed with deionized water and dried to obtain the pure-phase V2O3 single crystal with a size of about 2.5 mm, which has a low-temperature insulator phase to high-temperature metal phase transition near the characteristic temperature of 260 K, and the triggered resistivity mutation degree is 1000 times.

[0068] Example 24: V, VO2 were weighed according to the elemental molar ratio V:VO2 = 5.5:0.5, and were placed in a agate mortar and ground thoroughly. Then KCl was weighed according to the molar ratio VO2:KCl = 1:10, and was added to the mixed VO2 and metal V powder, which was ground again thoroughly. The mixture was cold-pressed into a 10 mm diameter pellet using a press, and was then placed in an alumina crucible. The pellet was sintered at 900 °C for 30 minutes, and then was kept at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10 Pa. After the reaction was completed, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure phase V6O11 single crystal. The low-temperature insulator phase transforms to a high-temperature metal phase near the characteristic phase transition temperature of 170 K, triggering a 100-fold change in resistivity. -5 -10 -4 Pa range, first sintered at 900 °C for 30 minutes, and then kept at 800 °C for 24 hours. After the reaction was completed, the pellet was cooled to room temperature at a rate of 0.1 °C / min using water as a coolant. Finally, the powder sample was rinsed with deionized water and dried to obtain pure phase V3O5 powder. The ceramic material of this component was obtained by adding a binder to the obtained powder, cold-pressing, and sintering. The low-temperature insulator phase transforms to a high-temperature metal phase near the characteristic phase transition temperature of 420 K, triggering a 10-fold change in resistivity. 11 single crystal, which transforms from a low-temperature insulator phase to a high-temperature metal phase near the characteristic phase transition temperature of 170 K, triggering a 100-fold change in resistivity.

[0069] Example 25: V, VO2 were weighed according to the elemental molar ratio V:VO2 = 2.5:0.5, and were placed in a agate mortar and ground thoroughly. Then KCl was weighed according to the molar ratio VO2:KCl = 1:10, and was added to the mixed VO2 and metal V powder, which was ground again thoroughly. The mixture was cold-pressed into a 10 mm diameter pellet using a press, and was then placed in an alumina crucible. The pellet was sintered at 900 °C for 30 minutes, and then was kept at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10 Pa. After the reaction was completed, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure phase V6O11 single crystal. The low-temperature insulator phase transforms to a high-temperature metal phase near the characteristic phase transition temperature of 170 K, triggering a 100-fold change in resistivity. -8 -10 -7 Pa range, first sintered at 900 °C for 30 minutes, and then kept at 800 °C for 24 hours. After the reaction was completed, the pellet was cooled to room temperature at a rate of 0.1 °C / min using water as a coolant. Finally, the powder sample was rinsed with deionized water and dried to obtain pure phase V3O5 powder. The ceramic material of this component was obtained by adding a binder to the obtained powder, cold-pressing, and sintering. The low-temperature insulator phase transforms to a high-temperature metal phase near the characteristic phase transition temperature of 420 K, triggering a 10-fold change in resistivity.

[0070] Example 26: V, VO2 were weighed according to the elemental molar ratio V:VO2 = 3.5:0.5, and were placed in a agate mortar and ground thoroughly. Then KCl was weighed according to the molar ratio VO2:KCl = 1:10, and was added to the mixed VO2 and metal V powder, which was ground again thoroughly. The mixture was cold-pressed into a 10 mm diameter pellet using a press, and was then placed in an alumina crucible. The pellet was sintered at 900 °C for 30 minutes, and then was kept at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10 Pa. After the reaction was completed, the pellet was cooled to room temperature at a rate of 0.1 °C / min. Finally, the powder sample was rinsed with deionized water and dried to obtain pure phase V6O11 single crystal. The low-temperature insulator phase transforms to a high-temperature metal phase near the characteristic phase transition temperature of 170 K, triggering a 100-fold change in resistivity. -7 -10 -6The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after the reaction, using water as a coolant, quenching to room temperature. Finally, the powder samples were washed with deionized water and dried to obtain pure phase V4O7powder, the obtained powder was added with a binder and cold-pressed to obtain ceramic materials of this component, which occurred low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 250 K, and the triggered resistivity mutation degree was 100 times.

[0071] Example 27: V and VO2 were weighed according to the element molar ratio V:VO2=4.5:0.5, and were placed in an agate mortar for grinding, then KCl was weighed according to the molar ratio VO2:KCl=1:10, and was added to the uniformly mixed VO2 and metal V powder, and was again ground uniformly, and was cold-pressed into a block with a diameter of 10 mm by a press, and was then placed in an alumina crucible, and was sintered at 800 °C for 24 hours in an oxygen partial pressure of 10~5Pa, after the reaction, using water as a coolant, quenching to room temperature. Finally, the powder samples were washed with deionized water and dried to obtain pure phase V5O9powder, the obtained powder was added with a binder and cold-pressed to obtain ceramic materials of this component, which occurred low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 130 K, and the triggered resistivity mutation degree was 200 times. -6 -10 -5 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after the reaction, using water as a coolant, quenching to room temperature. Finally, the powder samples were washed with deionized water and dried to obtain pure phase V4O7powder, the obtained powder was added with a binder and cold-pressed to obtain ceramic materials of this component, which occurred low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 250 K, and the triggered resistivity mutation degree was 100 times.

[0072] Example 27: V and VO2 were weighed according to the element molar ratio V:VO2=4.5:0.5, and were placed in an agate mortar for grinding, then KCl was weighed according to the molar ratio VO2:KCl=1:10, and was added to the uniformly mixed VO2 and metal V powder, and was again ground uniformly, and was cold-pressed into a block with a diameter of 10 mm by a press, and was then placed in an alumina crucible, and was sintered at 800 °C for 24 hours in an oxygen partial pressure of 10~5Pa, after the reaction, using water as a coolant, quenching to room temperature. Finally, the powder samples were washed with deionized water and dried to obtain pure phase V5O9powder, the obtained powder was added with a binder and cold-pressed to obtain ceramic materials of this component, which occurred low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 130 K, and the triggered resistivity mutation degree was 200 times. -5 -10 -4 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after the reaction, using water as a coolant, quenching to room temperature. Finally, the powder samples were washed with deionized water and dried to obtain pure phase V4O7powder, the obtained powder was added with a binder and cold-pressed to obtain ceramic materials of this component, which occurred low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 250 K, and the triggered resistivity mutation degree was 100 times. 11 The powders were sintered in a vacuum or inert atmosphere with precise control of the pressure in the range of 10~3~10~5Pa, first at 900 °C for 30 minutes, then at 800 °C for 24 hours, after the reaction, using water as a coolant, quenching to room temperature. Finally, the powder samples were washed with deionized water and dried to obtain pure phase V4O7powder, the obtained powder was added with a binder and cold-pressed to obtain ceramic materials of this component, which occurred low-temperature insulator phase to high-temperature metal phase transition near the phase transition characteristic temperature 250 K, and the triggered resistivity mutation degree was 100 times.

[0073] Example 29: VO2 and TiO2 are weighed in the elemental molar ratio VO2:TiO2 = 0.95:0.05, and are placed in a agate mortar and ground thoroughly and uniformly. Then KCl is weighed in the molar ratio VO2:KCl = 1:10, and is added to the uniformly mixed VO2 and TiO2 powder, which is again ground thoroughly and uniformly. The mixture is cold-pressed into a 10 mm diameter pellet using a press, and is then placed in an alumina crucible. The pellet is sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10 Pa. After the reaction is complete, the pellet is quenched to room temperature using water as a coolant. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase VTiO2 powder. The ceramic material of this composition is obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 320 K, and the triggered resistivity mutation degree is 100 times. -4 -10 -3 Pa range, first sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours. After the reaction is complete, the pellet is quenched to room temperature using water as a coolant. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase V 0.95 Ti 0.05 O2 powder. The ceramic material of this composition is obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 320 K, and the triggered resistivity mutation degree is 100 times.

[0074] Example 30: VO2 and Cr2O3 are weighed in the elemental molar ratio VO2:Cr2O3 = 0.95:0.05, and are placed in a agate mortar and ground thoroughly and uniformly. Then KCl is weighed in the molar ratio VO2:KCl = 1:10, and is added to the uniformly mixed VO2 and Cr2O3 powder, which is again ground thoroughly and uniformly. The mixture is cold-pressed into a 10 mm diameter pellet using a press, and is then placed in an alumina crucible. The pellet is sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10 Pa. After the reaction is complete, the pellet is quenched to room temperature using water as a coolant. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase V -4 -10 -3 Pa range, first sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours. After the reaction is complete, the pellet is quenched to room temperature using water as a coolant. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase V 0.9 Cr 0.1 O2 powder. The ceramic material of this composition is obtained by adding a binder to the obtained powder and sintering after cold-pressing. A low-temperature insulator phase to high-temperature metal phase transition occurs near the phase transition characteristic temperature of 360 K, and the triggered resistivity mutation degree is 10 times.

[0075] Example 31: VO2 and WO3 are weighed in the elemental molar ratio VO2:WO3 = 0.99:0.01, and are placed in a agate mortar and ground thoroughly and uniformly. Then KCl is weighed in the molar ratio VO2:KCl = 1:10, and is added to the uniformly mixed VO2 and WO3 powder, which is again ground thoroughly and uniformly. The mixture is cold-pressed into a 10 mm diameter pellet using a press, and is then placed in an alumina crucible. The pellet is sintered at 900 °C for 30 minutes, and then at 800 °C for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure in the range of 10-10 Pa. After the reaction is complete, the pellet is quenched to room temperature using water as a coolant. Finally, the powder sample is rinsed with deionized water and dried to obtain pure phase V -4 -10 -3The V2O3 powder is obtained by sintering the mixed powder at 900 ℃ for 30 minutes and then at 800 ℃ for 24 hours in a vacuum or inert atmosphere with precise control of the pressure in the range of 10-2Pa. After the reaction, the powder sample is washed with deionized water and dried. The ceramic material of this component is obtained by adding a binder to the obtained powder, cold pressing and then sintering. The low-temperature insulator phase to high-temperature metal phase transition occurs near the characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times. 0.99 W 0.01 The V2O3 powder is obtained by sintering the mixed powder at 900 ℃ for 30 minutes and then at 800 ℃ for 24 hours in a vacuum or inert atmosphere with precise control of the pressure in the range of 10-2Pa. After the reaction, the powder sample is washed with deionized water and dried. The ceramic material of this component is obtained by adding a binder to the obtained powder, cold pressing and then sintering. The low-temperature insulator phase to high-temperature metal phase transition occurs near the characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times.

[0076] Example 32: V and NaVO3 are weighed according to the element molar ratio V: NaVO3 = 2:3, and then placed in a agate mortar for grinding. KCl with a molar ratio of VO2: KCl = 1:10 is weighed, added to the uniformly mixed NaVO3 and metal V powder, and then ground again. The mixture is cold-pressed into a block with a diameter of 10 mm using a press. The block is then placed in an alumina crucible and sintered at 800 ℃ for 24 hours in an oxygen partial pressure of 10-2Pa. After the reaction, the block is cooled to room temperature at a cooling rate of 5 ℃ / min. Finally, the powder sample is washed with deionized water and dried to obtain pure phase V2O3 powder. The ceramic material of this component is obtained by adding a binder to the obtained powder, cold pressing and then sintering. The low-temperature insulator phase to high-temperature metal phase transition occurs near the characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times. -10 -10 -8 The V2O3 powder is obtained by sintering the mixed powder at 900 ℃ for 30 minutes and then at 800 ℃ for 24 hours in a vacuum or inert atmosphere with precise control of the pressure in the range of 10-2Pa. After the reaction, the powder sample is washed with deionized water and dried. The ceramic material of this component is obtained by adding a binder to the obtained powder, cold pressing and then sintering. The low-temperature insulator phase to high-temperature metal phase transition occurs near the characteristic temperature of 168 K, and the triggered resistivity mutation degree is 100 times.

[0077] The above description is only a preferred embodiment of the present application, and is not intended to limit the scope of the technical content of the present application. The technical content of the present application is broadly defined in the scope of the claims, and any technical entity or method that is the same as or equivalent to the claims defined in the application is considered to be covered by the claims.

Claims

1. A method for producing an intermediate valence state vanadium oxide electronic phase transition material, characterized by A synthesis method is provided to realize growth of vanadium oxide materials with intermediate valence vanadium elements and simultaneously introduce doping elements; the preparation method synthesizes VO2, magneli phase V n O 2n-1 , V2O3, wurtzite phase V n O 2n+1 ; Wherein, 3n9; synergistic vanadium valence control and transition group metal element doping, realize the continuous control of the electronic phase transition temperature in the wide range of 40-450 K; the method comprises the following steps: 1) According to the metal insulator electronic phase transition characteristics to be realized, select the vanadium element and oxide with higher or lower valence than the target intermediate valence vanadium oxide as the precursor, select the substance with higher or lower valence than the target intermediate valence vanadium element from the metal vanadium powder, low-toxicity VO2, V2O5 and NaVO3, and add the doping metal oxide, and determine the amount-of-substance ratio of the vanadium-containing precursor and the doping metal oxide according to the principles of element mass conservation and element electron transfer conservation before and after synthesis, weigh and mix thoroughly; 2) According to the temperature of the subsequent solid phase reaction to be used, add a fluxing agent with a certain melting point, and add the selected fluxing agent to the above-mentioned precursor mixed powder in a certain proportion, and mix again uniformly; 3) Adopting annealing process under certain atmosphere, first, the precursor with alkali metal halide fluxing agent is heated to above the melting point of the fluxing agent at an oxygen partial pressure in a certain range in vacuum or inert atmosphere, and the temperature is raised at a rate of 10 ℃ / min, so that the precursor is fully dissolved in the molten fluxing agent, and the precise control of the valence of the vanadium element in the intermediate valence vanadium oxide to be synthesized is ensured; then slowly cool to below the melting point of the fluxing agent, and after a certain period of time, cool to room temperature at a set cooling rate, which is the intermediate valence vanadium oxide to be prepared generated in the cooling process under vacuum or inert gas atmosphere, and co-precipitated with the gradually solidified alkali metal halide molten salt; the alkali metal halide fluxing agent in the obtained powder product is removed by water washing, thereby obtaining intermediate valence vanadium oxide powder or single crystal; the obtained powder is further cold-pressed and sintered to obtain intermediate valence vanadium oxide ceramic; Step 1) by regulating the valence state of vanadium element in intermediate valence state vanadium oxide and combining substitution of vanadium element by main group metal elements or transition group metal elements, realizing regulation of material metal insulator phase transition characteristic triggering temperature in the range of 40-450 K; wherein the valence state of vanadium element is controlled by metallic vanadium powder, VO2, V2O5 and NaVO3, including the following components: V2O3, V3O5, V4O7, V5O9, V6O 11 , VO2, V6O 13 ; transition group elements include Cr, Ti, Mo, Fe, W, Nb, Zr.

2. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase transition material is represented by the formula: ###0001### wherein x is a number between 0.1 and 0.

9. In the synthesis of V2O3, transition group doping elements Cr, Ti, Mo, Fe, Zr, main group doping elements include Al, Ga, In; fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, using a single flux to assist new phase growth, or using KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl multiple fluxes to assist new phase growth; the melting point of the flux is required to be lower than the melting point required for the synthesis of V2O3, and the precursor powder can be dissolved in the flux at high temperature to make the precursor powder uniformly dispersed in the flux at high temperature, thereby accelerating the reaction rate; the mixture of the precursor of the material to be synthesized and the flux is kept at 800-900 ℃ for 24 hours in a vacuum or inert atmosphere precisely controlled in the oxygen partial pressure range of 10 -10 -10 -8 Pa, and cooled to room temperature at a cooling rate of 2-5 ℃ / min to obtain V2O3 pure phase powder.

3. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase transition material is represented by the formula: ###0001### wherein x is a number between 0.1 and 0.

9. The doping metal element is Cr, Al, Ga, In, and the doping V2O3 has different characteristic temperature triggered metal-insulator phase transition, i.e. the transition from low-temperature insulator phase to high-temperature metal phase occurs at about 170 K, and the transition from low-temperature metal phase to high-temperature insulator phase occurs at about 380 K.

4. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0001### wherein x is a number between 0.1 and 0.

9. In the synthesis of intermediate valence vanadium oxide V3O5 in the magneli phase, transition group doping elements include Cr, Ti, Mo, Nb, Fe; fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, using a single flux to assist the growth of a new phase, or using a mixture of KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl to assist the growth of a new phase; the melting point of the flux is required to be lower than the melting point required for the synthesis of V3O5, and the flux can dissolve the precursor powder in a high-temperature liquid state, so that the precursor powder is uniformly dispersed in the flux at high temperature, and the reaction rate is accelerated; the mixture of the precursor of the material to be synthesized and the flux is heated to 820-920 ℃ in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10 -8 -10 -7 Pa, and is kept at this temperature for 24 hours, and is cooled to room temperature at a cooling rate of 2-5 ℃ / min, to obtain V3O5 pure phase powder.

5. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0001### wherein x is a number between 0.1 and 0.

9. The transition group doping elements in the synthesis of intermediate valence vanadium oxide V4O7 in the magneli phase include Cr, Ti, Mo, Nb, Fe; the fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single flux is used to assist the growth of a new phase, or a plurality of fluxes such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl are mixed to assist the growth of a new phase; the melting point of the flux is required to be lower than the melting point required for the synthesis of V4O7, and the precursor powder can be dissolved in the flux at high temperature to make the precursor powder uniformly dispersed in the flux at high temperature, thereby accelerating the reaction rate; the mixture of the precursor of the material to be synthesized and the flux should be in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10 -7 -10 -6 Pa, heat treated at 830-930 ℃ for 24 hours, and cooled to room temperature at a cooling rate of 2-5 ℃ / min to obtain V4O7 pure phase powder.

6. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0001### wherein x is a number between 0.1 and 0.

9. In the synthesis of intermediate valence vanadium oxide V5O9 in the magneli phase, transition group doping elements include Cr, Ti, Mo, Nb, Fe; fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, using a single flux to assist the growth of a new phase, or using a mixture of KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl to assist the growth of a new phase; the melting point of the flux is required to be lower than the melting point required for the synthesis of V5O9, and the flux can dissolve the precursor powder in a high-temperature liquid state, so that the precursor powder is uniformly dispersed in the flux at high temperature, and the reaction rate is accelerated; the mixture of the precursor of the material to be synthesized and the flux should be heated at 840-940 ℃ for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10 -6 -10 -5 Pa, cooled to room temperature at a cooling rate of 2-5 ℃ / min, and V5O9 pure phase powder is obtained.

7. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0001### wherein x is a number between 0.1 and 0.

9. Synthesis of intermediate valence vanadium oxide V6O 11 In the present application, the transition group doping elements include Cr, Ti, Mo, Nb, Fe; the fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, and a single flux is used to assist the growth of new phase, or multiple fluxes are used to assist the growth of new phase, such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl; the melting point of the fluxes is required to be lower than the melting point of the synthesized V6O 11 The melting point of the fluxes is required to be lower than the melting point of the synthesized V6O -5 -10 -4 The mixture of the precursor and the fluxes is required to be in a vacuum or inert atmosphere with an oxygen partial pressure of 10 11 Pa, and the temperature is kept at 850-950 ℃ for 24 hours, and then cooled to room temperature at a cooling rate of 2-5 ℃ / min, to obtain V6O 8. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0002### wherein x is a number between 0.1 and 0.

9. In the synthesis of doped VO2, transition group doping elements include Cr, Ti, Mo, Fe, W, Nb; fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, using a single flux to assist new phase growth, or using KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl multiple fluxes to assist new phase growth; the melting point of the flux is required to be lower than the melting point required for the synthesis of doped VO2, and the flux can dissolve the precursor powder in a high-temperature liquid state, so that the precursor powder is uniformly dispersed in the flux at high temperature, and the reaction rate is accelerated; the mixture of the precursor of the material to be synthesized and the flux should be heated at 850-950 ℃ for 24 hours in a vacuum or inert atmosphere with an oxygen partial pressure precisely controlled in the range of 10 -4 -10 -2 Pa, cooled to room temperature at a cooling rate of 2-5 ℃ / min, and doped VO2 pure phase powder is obtained; by adjusting the type and proportion of transition group doping elements, the metal-insulator phase transition temperature of VO2 can be flexibly controlled in the temperature range of 100-400 K.

9. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0002### wherein x is a number between 0.1 and 0.

9. Synthesis of intermediate valence vanadium oxide V6O 13 In the present application, the transition group doping elements include Cr, Ti, Nb, Mo; the fluxes include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, a single flux is used to assist the growth of new phase, or multiple fluxes are used to assist the growth of new phase, such as KCl and RbCl, KCl and NaCl, CsCl and LiBr, KCl and LiCl, NaCl and LiCl; the melting point of the fluxes is required to be lower than the melting point of the synthesized V6O 13 The melting point of the fluxes is required to be lower than the melting point of the synthesized V6O -5 -10 -3 The mixture of the precursor and the fluxes is required to be in a vacuum or inert atmosphere with an oxygen partial pressure of 10 13 Pa, and the temperature is required to be controlled within ± 1 ℃, and the temperature is required to be kept at 650-750 ℃ for 24 hours, and the temperature is required to be cooled to room temperature at a cooling rate of 5 ℃ / min, to obtain V6O 10. The method of claim 1, wherein the intermediate valence vanadium oxide electronic phase change material is represented by the formula: ###0001### wherein x is in the range of 0.1 to 0.

9. In step 3), by controlling the cooling rate, the grain size of the material can be flexibly controlled.

11. The method for preparing an intermediate valence vanadium oxide electronic phase transition material as described in claim 10, characterized in that, Cool slowly from a certain reaction temperature to room temperature at a cooling rate of 0.01-1 ℃ / min, finally synthesize intermediate valence vanadium oxide single crystal grown in a specific crystal direction, the grain size range is 1-5 mm; or cool slowly from a certain reaction temperature to room temperature at a cooling rate of 2-5 ℃ / min, finally synthesize intermediate valence vanadium oxide pure phase powder, the grain size range is 30-50 μm; or water as coolant, quenching from a certain reaction temperature to room temperature, obtain pure phase powder with grain size range of 5-10 μm.

Images