Ferromagnetic material, preparation method thereof and sensor
阅读说明：本技术 铁磁材料及其制备方法、传感器 (Ferromagnetic material, preparation method thereof and sensor ) 是由 于浦 张建兵 王猛 于 2018-06-07 设计创作，主要内容包括：本发明涉及一种铁磁材料。所述铁磁材料的结构式为A<Sub>3</Sub>B<Sub>3</Sub>O<Sub>8</Sub>。其中A为碱土金属元素和稀土金属元素中的一种或多种。B为过渡族金属元素的一种或多种,所述铁磁材料为二维金属态氧化物材料。所述铁磁材料的结构稳定,结晶质量较高,具备二维铁磁金属特性。所述铁磁材料在低温具有很明显的磁各向异性。所述铁磁材料的铁磁转变温度大约在200K。所述铁磁材料具有沿面内方向准二维的电导特性。所述铁磁材料可以广泛的应用到电磁传感器领域。(The present invention relates to a ferromagnetic material. The structural formula of the ferromagnetic material is A 3 B 3 O 8 . Wherein A is one or more of alkaline earth metal elements and rare earth metal elements. B is one or more of transition group metal elements, and the ferromagnetic material is a two-dimensional metallic oxide material. The ferromagnetic material has stable structure, high crystallization quality and two-dimensional ferromagnetic metal characteristics. The ferromagnetic material has a significant magnetic anisotropy at low temperatures. The ferromagnetic transition temperature of the ferromagnetic material is approximately 200K. The ferromagnetic material has a conductivity characteristic that is quasi-two-dimensional along an in-plane direction. The ferromagnetic material can be widely applied to the field of electromagnetic sensors.)
1. The ferromagnetic material is characterized in that the structural formula of the ferromagnetic material is A3B3O8Wherein A is one or more of an alkaline earth metal element and a rare earth metal element, and B is one or more of a transition group metal element, andThe ferromagnetic material is a two-dimensional metallic oxide material.
2. The ferromagnetic material of claim 1 wherein the alkaline earth metal comprises one or more of Be, Mg, Ca, Sr, Ba, the rare earth metal element comprises one or more of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and the transition group metal element comprises one or more of Co, Cr, Fe, Mn, Ni, Cu, Ti, Zn, Sc, and V.
3. The ferromagnetic material according to claim 1, wherein A is Ca element, B is Co element, and the ferromagnetic material is Ca3Co3O8。
4. the ferromagnetic material according to claim 3, wherein the ferromagnetic material Ca is3Co3O8the resistivity at 0-30 ℃ is 500 [ mu ] omega cm or less.
5. A method for preparing a ferromagnetic material, comprising the steps of:
S10, providing a reactant containing an element A, an element B and an oxygen element, and an oxidant, wherein the element A is one or more of an alkaline earth metal element and a rare earth metal element, and the element B is one or more of transition group metal elements;
S20, contacting the reactant and the oxidant and carrying out oxidation reaction to obtain the compound A3B3O8The ferromagnetic material of (1), the ferromagnetic material A3B3O8Is a two-dimensional metallic oxide material.
6. The method for preparing a ferromagnetic material as defined in claim 5, wherein in step S10, the reactant is Ca2Co2O5The oxidant is a mixture of oxygen and ozone.
7. The method for producing a ferromagnetic material as defined in claim 6, wherein said mixture of oxygen and ozone is generated by an ozone generator.
8. The method for preparing a ferromagnetic material as defined in claim 7, wherein said ozone generator generates said mixture of oxygen and ozone by:
and oxygen is filled into the ozone generating device, and under the action of ultraviolet rays, oxygen molecules are combined with oxygen molecules to generate ozone.
9. The method for preparing a ferromagnetic material as defined in claim 7, wherein said step S20 includes:
S201, reacting the reactant Ca2Co2O5Is arranged in the ozone generating device to form a reaction system in which the reactant Ca2Co2O5Is fully contacted with the mixture consisting of the oxygen and the ozone;
S202, heating the reaction system to 150-300 ℃ to enable the reaction system to generate oxidation reaction, wherein oxygen atoms are inserted into the reactant Ca2Co2O5To obtain Ca3Co3O8the ferromagnetic material of (1), the ferromagnetic material Ca3Co3O8Is a two-dimensional metallic oxide material.
10. A sensor, characterized in that the magnetoelectric conversion layer of the sensor adopts the ferromagnetic material of the two-dimensional metal state oxide according to any one of claims 1 to 4, and the sensor obtains the change of the magnitude and direction of the external magnetic field by detecting the change of the resistance of the magnetoelectric conversion layer.
Technical Field
The invention relates to the field of materials, in particular to a ferromagnetic material, a preparation method thereof and a sensor.
background
Most material structures in nature are three-dimensional, and the magnetic properties and the electrical properties of the materials are most expressed as three-dimensional characteristics. The material with three-dimensional characteristics has no obvious difference in the in-plane and out-of-plane directions. Under certain conditions, on the surface of a three-dimensional material or on both three dimensionsAt the interface of the material, a two-dimensional magnetic layer or a special electronic state different from the bulk material is formed. For example, LaAlO on the surface of three-dimensional topological insulator3/SrTiO3The interfaces of the heterojunctions are all insulators, and the surfaces or interfaces are two-dimensional metal states. And LaAlO3/SrTiO3The interfacial layer will also be ferromagnetic at low temperatures (both bulk materials are diamagnetic).
currently, in addition to surfaces and interfaces, the desire to achieve magnetic and metallic properties with quasi-two dimensions in three-dimensional materials generally requires materials with significant in-plane out-of-plane anisotropy in structure. In solid oxides, it is common to form an+ 1BnO3n+1The Ruddlesden-Popper (R-P) phase structure of (1). For example in La3-xSrxMn2O7、Sr2RuO4The magnetic and electric properties of the materials are mainly influenced by transition metal atoms Mn and Ru at the B position, and the magnetic metal layers of MnO or RuO are separated by two layers of Sr/La through orderly modulation of the A position, so that the materials show two-dimensional magnetoelectric characteristics. Other two-dimensional oxide material systems with surface characteristics also comprise a Dion Jacobson (D-J) structure with an alkali metal ion inserted on the basis of a perovskite structure, and a Bi inserted2O2aurivillius (AV) structures of layers, copper oxide superconductors having copper oxide layers, and the like.
Disclosure of Invention
Therefore, it is necessary to provide a ferromagnetic material, a preparation method thereof, and a sensor, aiming at the problems of complicated preparation method, high preparation difficulty, and low quality of a two-dimensional metallic ferromagnetic material.
A ferromagnetic material with a structural formula of A3B3O8Wherein A is one or more of alkaline earth metal elements and rare earth metal elements, B is one or more of transition group metal elements, and the ferromagnetic material is a two-dimensional metallic oxide material.
In one embodiment, the alkaline earth metal comprises one or more of Be, Mg, Ca, Sr, Ba, the rare earth metal element comprises one or more of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb, and the transition group metal element comprises one or more of Co, Cr, Fe, Mn, Ni, Cu, Ti, Zn, Sc and V.
In one embodiment, a is Ca element, B is Co element, and the ferromagnetic material is Ca3Co3O8。
In one embodiment, the ferromagnetic material Ca3Co3O8The resistivity at 0-30 ℃ is 500 [ mu ] omega cm or less.
A method for preparing a ferromagnetic material, comprising the steps of:
S10, providing a reactant containing an element A, an element B and an oxygen element, and an oxidant, wherein the element A is one or more of an alkaline earth metal element and a rare earth metal element, and the element B is one or more of transition group metal elements;
S20, contacting the reactant and the oxidant and carrying out oxidation reaction to obtain the compound A3B3O8the ferromagnetic material of (1), the ferromagnetic material A3B3O8Is a two-dimensional metallic oxide material.
In one embodiment, in the step S10, the reactant is Ca2Co2O5The oxidant is a mixture of oxygen and ozone.
In one embodiment, an ozone generating device is used to generate the mixture of oxygen and ozone.
In one embodiment, the step of generating the mixture of oxygen and ozone by the ozone generating device comprises:
And oxygen is filled into the ozone generating device, and under the action of ultraviolet rays, oxygen molecules are combined with oxygen molecules to generate ozone.
In one embodiment, the step S20 includes:
S201, reacting the reactant Ca2Co2O5Is arranged in the ozone generating device to form a reaction system in which the reactant Ca2Co2O5Is fully contacted with the mixture consisting of the oxygen and the ozone;
S202, heating the reaction system to 150-300 ℃ to enable the reaction system to generate oxidation reaction, wherein oxygen atoms are inserted into the reactant Ca2Co2O5In order to obtain Ca with the structural formula3Co3O8The ferromagnetic material of (1), the ferromagnetic material Ca3Co3O8Is a two-dimensional metallic oxide material.
A sensor, the magnetoelectric conversion layer of sensor adopts the ferromagnetic material in any one of the above embodiments, and the sensor obtains the change that the size and the direction of external magnetic field take place through detecting the change of magnetoelectric conversion layer resistance.
The structural formula of the ferromagnetic material provided in the embodiment of the application is A3B3O8. Wherein A is one or more of alkaline earth metal elements and rare earth metal elements. B is one or more of transition group metal elements, and the ferromagnetic material is a two-dimensional metallic oxide material. The ferromagnetic material has stable structure, high crystallization quality and two-dimensional ferromagnetic metal characteristics. The ferromagnetic material has a significant magnetic anisotropy at low temperatures. The ferromagnetic transition temperature of the ferromagnetic material is about 200K. The ferromagnetic material has a conductivity characteristic that is quasi-two-dimensional along an in-plane direction. The ferromagnetic material can be widely applied to the field of electromagnetic sensors.
Drawings
FIG. 1 is a flow chart of a method for preparing a ferromagnetic material according to an embodiment of the present application;
FIG. 2 shows the structural formula A in the example of the present application3B3O8The atomic structural diagram of the ferromagnetic material of (a);
FIG. 3 shows structural formula A obtained by scanning transmission electron microscopy in the examples of the present application3B3O8Of the ferromagnetic materialAn image;
FIG. 4 shows an example of the present application, in which 2 θ/ω scanning by X-ray diffractometer (XRD) is used to obtain a compound represented by formula A3B3O8Information of the out-of-plane lattice period of the ferromagnetic material;
FIG. 5 shows an example of the present application, in which a magnetic integrated test system is used to obtain a structural formula A3B3O8A macroscopic magnetic characterization of the ferromagnetic material of (a);
FIG. 6 shows a comparison of Ca with a physical property comprehensive test system in the examples of the present application2Co2O5And the ferromagnetic material Ca3Co3O8Measuring the resistivity of the substrate;
FIG. 7 shows the structural formula A in the examples of the present application3B3O8Fourier reflection spectra of different polarizations out of plane of the ferromagnetic material plane;
FIG. 8 shows the structural formula A in the examples of the present application3B3O8The thermal stability of the ferromagnetic material of (a);
FIG. 9 shows the structural formula A under different magnetic field conditions in the examples of the present application3B3O8The resistance of the ferromagnetic material.
Detailed Description
in order to make the objects, technical solutions and advantages of the present invention more clearly understood, the ferromagnetic material, the manufacturing method thereof and the sensor of the present invention are further described in detail below with reference to the accompanying drawings and the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In an embodiment of the present application, a ferromagnetic material is provided. The structural formula of the ferromagnetic material is A3B3O8Wherein A is one or more of alkaline earth metal elements and rare earth metal elements. B is one or more of transition group metal elements. The ferromagnetic material is a two-dimensional metallic oxide material. The alkaline earth metal comprises one or more of Be, Mg, Ca, Sr and Ba. The rare earth metal elements comprise La, Ce, Pr, Nd and PmOne or more of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb. The transition group metal elements comprise one or more of Co, Cr, Fe, Mn, Ni, Cu, Ti, Zn, Sc and V.
in one embodiment, a is Ca element, B is Co element, and the ferromagnetic material is Ca3Co3O8。
In one embodiment, the ferromagnetic material Ca3Co3O8the resistivity at 0-30 ℃ is 500 [ mu ] omega cm or less.
In the examples of the present application, the structural formula is A3B3O8The ferromagnetic material has quasi two-dimensional conductivity and ferromagnetic anisotropy, and has better oxygen ion mobility at 100-200 ℃.
Conventional A3B3O8The preparation method of the structure mainly comprises the steps of artificially modulating and growing, and firstly growing a layer of ABO3Film of the structure, regrowing a layer of A2B*2O5Structural film, alternating back and forth, constructed A3BB*2O8And has a similar oxygen defect modulation structure. Also, like La3Co3O8Is synthesized by LaCoO3Reacting with a reducing agent at high temperature, oxygen is lost, and La is contained in a metastable reduction product3Co3O8and (5) structure. The structural formula obtained by the two methods is A3B3O8The quality of the ferromagnetic material is not high, and the synthesized material does not have two-dimensional ferromagnetic metal characteristics and still is an antiferromagnetic insulator. The embodiment of the application provides a preparation method of a ferromagnetic material.
referring to fig. 1, a method for preparing the ferromagnetic material is provided in the embodiments of the present application. The method comprises the following steps:
And S10, providing a reactant containing an element A, an element B and an oxygen element, and an oxidant, wherein the element A is one or more of an alkaline earth metal element and a rare earth metal element, and the element B is one or more of transition group metal elements.
In the stepIn step S10, the alkaline earth metal includes one or more of Be, Mg, Ca, Sr, Ba. The rare earth metal elements comprise one or more of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb. The transition group metal elements comprise one or more of Co, Cr, Fe, Mn, Ni, Cu, Ti, Zn, Sc and V. For example, the reactant is the reactant with the ferromagnetic material A3B3O8The elements are the same, but the structural formula is different. The reactant can be oxidized to obtain a structural formula A3B3O8the ferromagnetic material of (a).
for example, in the preparation of said ferromagnetic material Ca3Co3O8Ca may be selected for use2Co2O5As the reactant. The oxidant can be one or more of oxygen, ozone or potassium permanganate. The oxidizing agents have different oxidizing abilities, and particularly, the corresponding oxidizing agents can be selected according to the reactants. The reaction conditions during which the oxidation reaction takes place may also be different for different selected said oxidizing agents.
S20, contacting the reactant and the oxidant and carrying out oxidation reaction to obtain the compound A3B3O8The ferromagnetic material of (1), the ferromagnetic material A3B3O8Is a two-dimensional metallic oxide material.
In step S20, an oxidation reaction occurs that primarily oxidizes the reactant to a compound of formula A3B3O8The ferromagnetic material of (a). For example, by means of the reactant Ca2Co2O5has a structure with one layer of Co-O tetrahedron and one layer of Co-O octahedron arranged crosswise. The reactant Ca2Co2O5Is an antiferromagnetic insulator. Reacting the reactant Ca2Co2O5Annealing in ozone at 300 deg.C, and oxidizing to obtain A3B3O8The ferromagnetic material of (a).
In this embodiment, the reactant and the oxidant may be sufficiently contactedContact and generate oxidation reaction to obtain the structural formula A3B3O8The ferromagnetic material of (a). The temperature at which the oxidation reaction takes place needs to be selected according to the different reactants and the different oxidants. The preparation method of the ferromagnetic material can obtain the ferromagnetic material which has quasi two-dimensional conductivity and ferromagnetic anisotropy and has better oxygen ion mobility at 100-200 ℃. The structural formula obtained in the examples of the application is A3B3O8The quality of the ferromagnetic material is high, and the synthetic ferromagnetic material has two-dimensional ferromagnetic metal characteristics.
In one embodiment, in step S10, the oxidizing agent is one or more of oxygen, ozone, or potassium permanganate. Since the temperature at which the oxidation reaction takes place needs to be selected according to the different reactants and the different oxidants. Thus, the oxidant may be oxygen. The oxidant may be ozone. The oxidant may be a mixed gas of oxygen and ozone. The oxidizing agent may also be solid potassium permanganate, provided that the oxidizing agent is capable of sufficient contact with the reactants and oxidation occurs.
In one embodiment, in the step S10, the reactant is Ca2Co2O5The oxidant is a mixture of oxygen and ozone, and the oxidant is generated by an ozone generating device. The selection of the ozone generating device in the present application is not particularly limited. The ozone generating device can be designed by self or purchased directly.
In one embodiment, the step of generating the mixture of oxygen and ozone by the ozone generating device comprises: and oxygen is filled into the ozone generating device, and under the action of ultraviolet rays, oxygen molecules are combined with oxygen molecules to generate ozone. Since ozone is its active oxide. A large amount of a mixture of ozone and oxygen is present in the ozone generating means for reacting with the reactant Ca2Co2O5The reaction was carried out sufficiently. In one embodiment, the step S20 includes:
S201, reacting the reactant Ca2Co2O5Is arranged in the ozone generating device to form a reaction system in which the reactant Ca2Co2O5And said mixture of oxygen and ozone.
S202, heating the reaction system to 150-300 ℃ to enable the reaction system to generate oxidation reaction, wherein oxygen atoms are inserted into the reactant Ca2Co2O5In order to obtain Ca with the structural formula3Co3O8The ferromagnetic material of (1), the ferromagnetic material Ca3Co3O8Is a two-dimensional metallic oxide material.
Specifically, the temperature at which the reaction system is heated needs to be slightly adjusted according to the conditions in the actual experimental process. An oxidation reaction occurs in the reaction system. The reactant of the oxidation reaction is the reactant Ca2Co2O5. The oxidizing agent for the oxidation reaction is a mixture of said oxygen and ozone. Final product of the oxidation reaction the ferromagnetic material Ca3Co3O8。
In this example, the final reaction product is the ferromagnetic material Ca3Co3O8. During the test, a test instrument can be connected to test the reaction product in real time to obtain the pure ferromagnetic material Ca3Co3O8。
Referring to fig. 2, in the embodiment of the present application, the above-mentioned method for preparing a ferromagnetic material is adopted, and the ferromagnetic material Ca is provided3Co3O8The atomic structural diagram of (1). As can be seen from FIG. 2, one layer of Co-O tetrahedra and two layers of Co-O octahedra are staggered as viewed in the out-of-plane direction. Ca obtained by growth2Co2O5Has a structure with one layer of Co-O tetrahedron and one layer of Co-O octahedron arranged crosswise. The Ca2Co2O5The Ca is an antiferromagnetic insulator2Co2O5Annealing treatment in ozone at 300 ℃.The Ca2Co2O5Carrying out oxidation reaction with oxygen atoms in the ozone to obtain the ferromagnetic material Ca3Co3O8. Referring to fig. 3, the atomic structure diagram of the sample before and after ozone annealing can be observed and photographed by a Scanning Transmission Electron Microscope (STEM). As shown in FIG. 3, the corresponding atoms have periodic structures in the out-of-plane direction, from 4 layers of Co-O to 3 layers of Co-O, i.e., the Ca2Co2O5Becomes the ferromagnetic material Ca3Co3O8。
Referring to fig. 4, correspondingly, the information of the out-of-plane lattice period of the entire sample can be obtained by 2 θ/ω scanning with an X-ray diffractometer (XRD). As shown in FIG. 4, Ca grown on LSAT (001) substrates2Co2O5A film. The LSAT substrate has a structural formula of (LaAlO)3)0.3(SrAl0.5Ta0.5O3)0.7. Further reacting the Ca with a catalyst2Co2O5annealing the film and ozone for one hour at the temperature of 300 ℃ to obtain the ferromagnetic material Ca3Co3O8. The out-of-plane lattice constant changed from 1.496nm to 1.115nm and the out-of-plane period changed from 4 to 3 Co-O layers as can be derived from the bragg diffraction formula. Illustrating the Ca2Co2O5The film is oxidized to obtain uniform high-quality Ca3Co3O8A film.
Referring to fig. 5, the ferromagnetic material Ca is tested by a comprehensive magnetic testing system (MPMS)3Co3O8The macroscopic magnetic properties of the films were measured. As can be seen in FIG. 5, the ferromagnetic material Ca3Co3O8Has a significant magnetic anisotropy at low temperatures. As shown in fig. 5(a), which is a hysteresis loop of magnetic moment (M) at 5K temperature varying with magnetic field (H), the in-plane signal has significantly larger saturation magnetic moment and coercive field relative to the out-of-plane signal. As shown in fig. 5(b), the ferromagnetic material Ca3Co3O8Has a ferromagnetic transition temperature of about 200K or so.
Referring to FIG. 6, the Ca is tested by a comprehensive physical Property testing System (PPMS)2Co2O5And the ferromagnetic material Ca3Co3O8Is measured. As shown in FIG. 6, the Ca2Co2O5The resistivity of (a) increases significantly with decreasing temperature and is an insulator. The ferromagnetic material Ca obtained by the reverse ozone treatment3Co3O8The resistivity of (a) is significantly reduced with temperature drop and is also small in absolute value. The ferromagnetic material Ca3Co3O8The resistivity at 0-30 deg.C can reach below 500 μ Ω cm. The ferromagnetic material Ca3Co3O8Obviously showing metallic characteristics.
Referring to FIG. 7, the ferromagnetic material Ca is provided3Co3O8Fourier-reflected spectra of different polarization out of plane in-plane. For metallic materials, the traveling electrons near the fermi level interact with the fermi level in response to photons, and are reflected in the light absorption (reflection). The anisotropy of electronic properties in materials can be judged by polarization (polarization) dependent mid-infrared fourier spectroscopy. As shown in fig. 7, the ferromagnetic material Ca is provided3Co3O8In-plane out-of-plane different polarization fourier reflection spectra. At the low wavenumber end, the in-plane reflected signal tends to increase sharply, being sharply reduced at that end compared to out-of-plane. Illustrating the ferromagnetic material Ca3Co3O8The in-plane direction metallic property is good, while the out-of-plane direction metallic property is severely suppressed. FIG. 7 shows the ferromagnetic material Ca as a whole3Co3O8Has quasi-two-dimensional conductivity characteristics along the in-plane direction.
Referring to FIG. 8, the embodiment of the present application, the ferromagnetic material Ca3Co3O8Is used for the characterization of thermal stability. Characterization of the ferromagnetic material Ca by high temperature heating in atmospheric environment3Co3O8Thermal stability of (2). The ferromagnetic material Ca is monitored in real time by XRD3Co3O8Changes with increasing temperature. As shown in fig. 8, one XRD spectrum was measured for each 20 ℃ temperature rise,below 220 ℃, the ferromagnetic material Ca3Co3O8no change occurred. Until the temperature is higher than 220 ℃, the ferromagnetic material Ca3Co3O8Start slow reduction to Ca2Co2O5. This indicates that the ferromagnetic material Ca3Co3O8Has good thermal stability at room temperature. Due to the Ca2Co2O5And the ferromagnetic material Ca3Co3O8The two phases can be oxidized and reduced at about 200 ℃, which shows that oxygen ions have good mobility near a temperature range of 20 ℃ to 200 ℃. The ferromagnetic material Ca3Co3O8The material becomes a material with good ionic and electronic conductivity at a temperature range of 20-200 ℃. Accordingly, the ferromagnetic material Ca3Co3O8Has potential application as electrode material of solid oxide fuel cell in the temperature region.
A magnetoelectric conversion layer of the sensor adopts a ferromagnetic material of the two-dimensional metal state oxide. The sensor obtains the change of the size and the direction of an external magnetic field by detecting the change of the resistance of the magnetoelectric conversion layer. For example, the sensor may be a magneto-electric sensor. The magnetoelectric conversion layer of the sensor adopts a structural formula A3B3O8The ferromagnetic material of (2) can realize accurate measurement of the sensor under simple structural arrangement.
referring to fig. 9, in the embodiment of the present application, the ferromagnetic material Ca is provided under different magnetic fields at a temperature of 50K3Co3O8Resistance of (d) is plotted. As can be seen in FIG. 9, when the magnetic field is perpendicular (black) or parallel (gray) to the film surface, the Ca, which is a ferromagnetic material, is swept from-9 Tesla to 9 Tesla3Co3O8The resistance value of (2) varies with the magnetic field strength. As can be seen from fig. 9: 1. based on the ferromagnetic material Ca3Co3O8The magnetic resistance effect is achieved below the Curie temperature of 200K, and the resistance value changes along with the change of an external magnetic field. 2. When the magnetic field is largeWhen the direction changes (e.g., from parallel to the surface of the film to perpendicular), the resistance value also changes. According to this, the ferromagnetic material Ca can be utilized3Co3O8And preparing a magnetoelectric induction element to induce the change of the magnitude and the direction of an external magnetic field.
In this embodiment, accurate measurement of the sensor can be realized by providing the magnetoelectric conversion layer. The traditional magnetoelectric sensor needs to be provided with an antiferromagnetic AFM layer and a ferromagnetic FM layer to realize the measurement of the size and the direction of a magnetic field. In this embodiment, the ferromagnetic material Ca is used3Co3O8Has anisotropic magnetoresistance. The resistance signal of the sensor can change along with the change of the magnitude and the space direction of an external magnetic field in a temperature range of 2K-200K. The sensor may be used to detect changes in the magnitude and spatial direction of the magnetic field. For example, when the magnitude of an external magnetic field changes or the direction of the magnetic field changes, the resistance of the magnetoelectric conversion layer of the sensor changes.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
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