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CN-116782747-B - Preparation method of near-room-temperature oversized anisotropic magnetoresistive film for flexible electronic compass

CN116782747BCN 116782747 BCN116782747 BCN 116782747BCN-116782747-B

Abstract

The invention discloses a preparation method of a near-room-temperature oversized anisotropic magnetoresistive film for a flexible electronic compass, which comprises the following steps: component design, precursor preparation, precursor filtration, wet film spin coating and dry film shaping, single film layer sintering, multi-film layer circulation and single-layer dispersion state metal composite phase preparation. The film prepared by the invention can obtain super-large anisotropic magnetic resistance under the action of external magnetic fields with different angles and low values, and has the advantages of response temperature reaching a near room temperature range, excellent transportation property, high strength, high toughness, high flexibility and the like. In addition, the preparation process provided by the invention is simple and convenient, has strong controllability and wide application prospect, and can be greatly popularized and applied particularly on positioning devices such as an angle sensor, an electronic compass and the like.

Inventors

  • YANG SHENGAN
  • DONG ZHILIANG
  • MA JI
  • CHEN QINGMING
  • CHEN RUI
  • ZHANG HUI
  • WU LIANG
  • Guo Najun

Assignees

  • 昆明理工大学

Dates

Publication Date
20260512
Application Date
20230808

Claims (9)

  1. 1. The preparation method of the near-room-temperature oversized anisotropic magnetoresistance film for the flexible electronic compass is characterized by comprising the following steps of: (1) Taking Re 1-x Ae x TmO 3 as a component, wherein Re is a rare earth element, ae is an alkaline earth element, tm is a transition metal element, and weighing rare earth raw materials, alkaline earth raw materials and transition metal raw materials according to the molar concentration and stoichiometric ratio of a precursor solution to obtain each initial raw material; (2) Preparing a precursor by adopting a non-water-based sol-gel process, dissolving the initial raw materials obtained in the step (1) in a quantitative solvent, stirring 20 min-30 min at a stirring rate of 200 rap/min-500 rap/min to form a precursor solution, adding a dispersing agent, a chelating agent and a binder into the precursor solution, adding the quantitative solvent to enable the precursor solution to reach a constant volume standard, and stirring at a stirring rate of 300 rap/min-800 rap/min for less than 12 hours to obtain a precursor with apparent viscosity of 0.35 Mpa.S-4.00 Mpa.S; (3) Filtering the precursor, namely extracting and filtering the precursor obtained in the step (2) to obtain Re 1- x Ae x TmO 3 filtering solution with the solute content of 85% -95%, then placing the solution in a vacuum drying environment with the vacuum degree of 5 MPa-8 MPa and the temperature of 30-40 ℃ to remove bubbles of less than 5h, and aging the solution of less than 30 h to obtain a high-purity precursor; (4) Selecting different substrates, annealing the substrates, placing the substrates on spin coating equipment, uniformly coating the high-purity precursor obtained in the step (3) on the substrates, spin coating to obtain a wet film, and drying and shaping the wet film in a dry environment to obtain a dry film; (5) Sintering the single film layer, namely sintering the dry film obtained in the step (4) to obtain the single film layer, wherein the sintering temperature is 800-1500 ℃, the heating rate is 5-30 ℃ per minute, and the sintering time is more than 10 minutes; (6) The multi-film layer circulation, namely taking the steps (4) and (5) as a process circulation reciprocating unit, wherein the circulation times are a times, and a is more than or equal to 1, so that the multi-film layer formed by overlapping single film layers as the minimum unit can be prepared; (7) Performing sputtering treatment on a metal target by a physical sputtering scheme for 10 s-1000: 1000 s, obtaining metal particles with dispersed distribution on the surface of the multilayer film with any number of layers obtained in the step (6), wherein the particle size range of the metal particles is 10 nm-500: 500 nm, and then performing sintering treatment II on the metal particles to obtain a single-layer dispersed metal composite phase, wherein the temperature of the sintering treatment II is 300-700 ℃, the heating rate is 3-30 ℃ and the sintering time is 10 min-100: 100 min, so as to obtain the metal-containing composite phase transition material; (8) And (3) cycling the multiple film layers, namely repeating the step (6) b times on the basis of the metal-containing composite phase transition material prepared in the step (7), wherein b is more than or equal to 1, and obtaining the multiple film layer heterostructure composite film.
  2. 2. The method of manufacturing a near room temperature super large anisotropic magnetoresistive film for a flexible electronic compass according to claim 1, wherein the stoichiometric ratio x of the Re 1-x Ae x TmO 3 component in step (1) is in the range of 0.05 to 0.5, the Re element comprises La, pr, nd, sm, gd, the Ae element comprises Ca and Sr, the Tm element comprises V, cr, mn, co, the composition design must contain Re, ae and Tm elements, the Re, ae and Tm elements are not limited to one, the molar concentration of the precursor solution is 2.0 mol/L to 3.6 mol/L, and the rare earth raw material, the alkaline earth raw material and the transition metal raw material are any one of nitrate, acetate or carbonate.
  3. 3. The method for preparing the near-room-temperature oversized anisotropic magnetoresistive film for the flexible electronic compass, which is characterized in that in the step (2), the quantitative solvent is alcohol or water or a mixed solution of the alcohol and the water, wherein the mixed proportion of the alcohol and the water is calculated according to a molar ratio, the molar ratio is in the range of 0.01:7-7:0.01, the constant volume standard is 90 ml-150 ml, the dispersing agent is ethylene glycol, the chelating agent is any one of calcium acetate, calcium chloride or citric acid, and the binder is any one of ethylenediamine or ethanolamine.
  4. 4. The method for preparing the near-room-temperature oversized anisotropic magnetoresistive film for the flexible electronic compass, which is characterized in that the different substrates in the step (4) comprise any one of strontium titanate substrates, sapphire substrates and mica substrates, the different substrates can be symmetrical or asymmetrical in shape, the area proportion range of the dissymmetry is less than or equal to 15%, the area of the substrate is 5mm 2 -100 mm 2 and the thickness of the substrate is 0.01 mm-5 mm, the annealing treatment procedure in the step (4) is divided into three stages, namely a first stage, heating, the heating rate is 3-30 ℃ per minute, a second stage, heat preservation, the heat preservation range is 500-1500 ℃, the heat preservation duration is 0.5-0.5 h.0 h, the cooling rate is 5-10 ℃ per minute, and the annealing treatment in each stage is completed in an inert atmosphere.
  5. 5. The method for preparing the near-room temperature oversized anisotropic magnetoresistive film for the flexible electronic compass, which is characterized in that the procedure of wet film spin coating in the step (4) is divided into three stages, namely, the first stage titration of 0.4 ml-4.0 ml high-purity precursor on a substrate, the spin coating of 20 s-40 s at the rotating speed of 600 rap/min-1000 rap/min to obtain a wet film layer I, the second stage titration of 0.3 ml-3.0 ml high-purity precursor on the surface of the wet film layer I, the spin coating of 20 s-30 s at the rotating speed of 1400 rap/min-3000 rap/min to obtain a wet film layer II, the third stage titration of 0.2 ml-2.0 ml high-purity precursor obtained in the step (3), the spin coating of 10 s-20 at the rotating speed of 4000 rap/min-8000 rap/min to obtain a wet film layer I, and the spin coating can be performed simultaneously with the spin coating or simultaneously with the spin coating.
  6. 6. The method for preparing the near-room-temperature oversized anisotropic magnetoresistive film for the flexible electronic compass, which is characterized in that the dry film shaping procedure in the step (4) is divided into three stages, namely, the first stage is to keep the temperature at 70-90 ℃ for 20 min-30 min, the temperature rising rate is 3-15 ℃ per minute, the second stage is to keep the temperature at 130-200 ℃ for 15 min-25 min, the temperature rising rate is 3-20 ℃ per minute, the third stage is to keep the temperature at 260-360 ℃ for 20 min-30 min, and the temperature rising rate is 3-30 ℃ per minute.
  7. 7. The method of claim 1, wherein the physical sputtering scheme used in the step (7) comprises any one of ion sputtering, magnetron sputtering and pulse laser deposition, and the dispersed metal composite phase element comprises any one of Au, ag, cu, pt.
  8. 8. The method for preparing the near-room-temperature oversized anisotropic magnetoresistive film for the flexible electronic compass, which is characterized in that the steps (7) and (8) are used as process cycle reciprocating units, the cycle times are n times and are more than or equal to 1, and the times b of the step (6) corresponding to repeated operations in the step (8) on different cycle times are quantitative, so that the symmetrical multi-film heterostructure composite film is obtained.
  9. 9. The method for preparing the near-room-temperature oversized anisotropic magnetoresistive film for the flexible electronic compass, which is characterized in that the steps (7) and (8) are used as process cycle reciprocating units, the cycle times are m times which are more than or equal to 1, and the times b of the repeated operation step (6) corresponding to the step (8) on different cycle times are variables, so that the asymmetric multi-film heterostructure composite film is obtained.

Description

Preparation method of near-room-temperature oversized anisotropic magnetoresistive film for flexible electronic compass Technical Field The invention belongs to the field of film materials, and particularly relates to a preparation method of a near-room-temperature super-large anisotropic magnetoresistive film for a flexible electronic compass. Background Because of the coupling effect among multiple degrees of freedom of crystal lattice, charge, spin, orbit and the like of perovskite oxides, unique electric transmission behaviors and magnetoresistance effects are generated, people pay attention to the magnetic resistance, electric transmission properties and various electromagnetic phenomena of the material. In particular perovskite Re 1-xAexTmO3 film materials, which exhibit the following rich physical properties. If the magnetic resistance is changed drastically and in different magnitudes in different directions, the magnetic resistance effect and Anisotropic Magnetic Resistance (AMR) performance are generated, the giant magnetoresistance phenomenon and spin polarization tunneling effect are generated in the metal-insulation competition mode, and the high-value resistance temperature coefficient is near the metal-insulation phase transition temperature. Based on the excellent and abundant physical characteristics, the Re 1-xAexTmO3 material has wide application prospect in the aspect of electronic devices such as angle sensors, electronic compass and other positioning devices. However, the material has weak magnetic resistance effect in a low magnetic field, poor anisotropic magnetic resistance performance, and the metal-insulation phase transition temperature is far away from room temperature, so that the application range and prospect of the film material are greatly limited. In recent years, the technology for preparing the perovskite Re 1-xAexTmO3 film has been developed rapidly, and is mainly divided into physical film making and chemical film making. Physical methods mainly include sputtering schemes such as molecular beam epitaxy, spray deposition, pulsed laser deposition, and the like. The chemical method mainly comprises a sol-gel combined spin coating process, an electrochemical deposition method, a metal organic compound chemical deposition method and the like. The chemical method for preparing the film has the advantages of low cost, simple operation and the like. The sol-gel combined spin coating process used at present has the advantages of 1) simple production process and mechanical equipment, no need of expensive instruments, simple requirements on environment and no need of harsh vacuum environment, 2) room temperature in the experimental process, which is very beneficial to preparing a material system which is easy to volatilize or change quality at high temperature, 3) precursor in a gel state is easy to prepare a film with uniform thickness distribution and high quality on a large-area substrate, 4) the purity of each component of the prepared film is high, and the stoichiometric ratio is easy to control for a doping system. However, the Re 1-xAexTmO3 film prepared by the physical method or the chemical method is still limited by film thickness, surface roughness, stress effect and the like, so that the film material has relatively high AMR value in an extremely low temperature state (such as a liquid helium temperature region) or has only extremely low AMR performance near room temperature, which cannot meet the use requirement of corresponding devices. Meanwhile, because the surface or interface of the Re 1-xAexTmO3 film prepared by a physical method is highly flat, if a metal composite phase is prepared between different Re 1-xAexTmO3 films to improve the AMR performance of the composite material, a preferential transport channel is formed on the metal composite phase, and the AMR value is not increased or reduced finally, so that a composite heterostructure of Re 1-xAexTmO3/metal/Re 1-xAexTmO3 sandwich structures with excellent AMR performance is never reported to be prepared. The Re 1-xAexTmO3 film prepared by adopting the sol-gel combined spin coating process can have certain uncontrollable roughness on the surface or interface, so that a large number of defect areas are reserved in the finally formed multi-film layer, and the AMR performance and the metal-insulation phase transition temperature are greatly influenced. Based on the problems, the heterostructure film material for the positioning device, such as an angle sensor, an electronic compass and the like, is obtained through the process preparation exploration and the performance optimization of the heterostructure film based on the anisotropic magnetoresistance effect. The magneto-electric property, mechanical property, chemical property and the like of the film can be improved by optimizing the selection of the film material, improving the surface structure of the film, optimizing the preparation process of the film, d