38 results about "Antiferromagnetism" patented technology

A bilayer film of a magnetic body and an insulator has an antiferromagnetic layer having a hexagonal crystal structure and at least one surface of which is the (10-10) surface of an antiferromagnetic body, and an insulator layer containing two or three or four atoms laminated on the (10-10) surface of the antiferromagnetic layer. A bilayer film of a magnetic body and an insulator has an antiferromagnetic layer having a hexagonal crystal structure and at least one surface of which is the (0001) surface of an antiferromagnetic body, and an insulator layer containing two or three or four atoms laminated on the (0001) surface of the antiferromagnetic layer. The tunneling magnetoresistive element has a second antiferromagnetic film layer laminated on the insulator of the bilayer film. The magnetic memory includes a plurality of the tunneling magnetoresistive elements.

This antiferromagnetic material has a hexagonal crystal structure (space group P63 / mmc) and has a composition of (Mn1-xAx)3Sn (0<x<0.15, A=Ti, V, Cr, Zr, Nb, Mo, Tc, Hf, Ta, W, Re) or Mn3Sn1-yBy (0<y<0.35, B=Sc, Ti, V, Ga, Y, Zr, Nb, In, Hf, Tl). A is preferably at least one of V and Cr. Also, B is preferably at least one of Ga, In, and Tl.

The invention relates to a manufacturing method of a magnetic sensor. The magnetic sensor includes at least one MR element and at least one magnetic field generator. The at least one MR element includes a magnetization-fixed layer and a free layer. The at least one magnetic field generating body includes a ferromagnetic part and an antiferromagnetic part that is exchange-coupled to the ferromagnetic part. A method for manufacturing a magnetic sensor includes a step of forming at least one MR element, and a step of forming at least one magnetic field generator. The step of forming the at least one magnetic field generating body includes: a step of forming at least one initial magnetic field generating body including an initial ferromagnetic part and an antiferromagnetic part that later become a ferromagnetic part; and a step for fixing the direction of magnetization of the initial ferromagnetic part using the laser and the external magnetic field so that the initial ferromagnetic part becomes a ferromagnetic part.

The invention relates to a magnetic sensor. This magnetic sensor is provided with: at least one MR element; a ferromagnetic layer configured to overlap the at least one MR element when viewed from the first direction; insulating layers disposed on both sides of the at least one MR element in the second direction; and an antiferromagnetic layer disposed over the at least one MR element, the ferromagnetic layer, and the insulating layer. The antiferromagnetic layer includes an antiferromagnetic portion facing the ferromagnetic layer, and a non-facing portion facing the at least one MR element and the insulating layer but not facing the ferromagnetic layer. There is no magnetic layer between the at least one MR element and the antiferromagnetic layer.

In order to reduce the amount of rare earth metals such as Ho or Er in a cold storage material for a cryogenic refrigerator, the cold storage material (15) for a cryogenic refrigerator contains crystals of CuFe1-xMxO2 (M is a metal element other than Fe), and in a temperature range of 10 K or less, CuFe1-xMxO2 exhibits antiferromagnetic properties and has a volumetric specific heat greater than that of lead.

To provide a thin thermoelectric conversion element having flexibility.SOLUTION: A thermoelectric transducer comprising: a substrate having flexibility; a base layer formed on the substrate and made of a metal-oxide material; and a magnetic layer laminated on the base layer and having conductivity and ferromagnetic or antiferromagnetic properties, wherein a thickness of the base layer is not less than 10nm and not more than 50nm.SELECTED DRAWING: Figure 1

To provide a quantum converter and a quantum conversion method capable of improving conversion efficiency even when light with low loss in an optical fiber is used.SOLUTION: The quantum transducer includes a three dimensional cavity resonator, and a nonmagnetic first insulator film and a ferromagnetic or antiferromagnetic second insulator film that are provided in the three dimensional cavity resonator and are stacked on each other, A laminate including an interface between the first insulator film and the second insulator film, a magnetic field application unit configured to apply a magnetic field including a component perpendicular to the interface to the laminate, and a microwave transmission and reception unit configured to transmit and receive microwaves to and from the laminate, wherein the first insulator film and the second insulator film do not include a topological insulator, the second insulator film has an easy magnetization axis along a first axis perpendicular to the interface, and the laminate is irradiated with laser light from a direction inclined with respect to the first axis. Quantum converters can be used, for example, in quantum computing.SELECTED DRAWING: Figure 1

The application discloses a multi-state memory unit based on anti-ferromagnetic, and relates to the technical field of spintronic devices, and aims to solve the problems that multi-bit storage of a single device cannot be realized and data writing is difficult in the prior art.The application comprises a magnetic tunnel junction, a bottom electrode layer serving as a current writing line, the magnetic tunnel junction is used for storing data, and the bottom electrode layer is used for providing spin-orbit torque to write data; the magnetic tunnel junction at least comprises a fixed layer, a barrier layer and a free layer; the free layer is adjacent to an anti-ferromagnetic layer, and exchange bias is formed between the anti-ferromagnetic layer and the free layer; a current is applied on the corresponding bottom electrode to reverse the direction of the free layer and the exchange bias to a direction perpendicular to the current; and the free layer and the exchange bias are controlled to reverse the angle by applying the current in the current writing line at different angles, so that more intermediate states can be obtained in the whole magnetic resistance range. Not only can the application realize magnetic field-free writing of data, but also can realize extremely stable multi-bit storage.

The invention belongs to the technical field of multiferroic materials, and relates to a design method of a multiferroic body based on a vanadium-doped two-dimensional ferroelectric and the multiferroic body. Performing cell expansion on the single-layer NbOI2 primitive cell in different directions to obtain supercells with different sizes; the method comprises the following steps: doping supercells with different sizes by taking vanadium as a doping element to obtain a doping configuration of each supercell under different doping concentrations; taking the doping configuration with the lowest total energy of the ferromagnetic state and the antiferromagnetic state under each doping concentration as the ground state configuration of the doping concentration; calculating band gaps Eg of ground state configurations with different doping concentrations and spontaneous ferroelectric polarization intensity along a b axis, drawing a double-Y-axis curve graph by taking the doping concentrations as abscissas and the spontaneous ferroelectric polarization intensity and the band gaps Eg as ordinates, and dividing a multiferroic phase region and a magnetic semimetal phase region to obtain a doping concentration-physical property evolution phase diagram; and obtaining a corresponding doping concentration value range when the ground state configuration has a multiferroic phase with ferroelectricity and antiferromagnetism so as to design a multiferroic body.

The antiferromagnetic material has a hexagonal crystal structure and has an antiferromagnetic layer containing Mn3A1-xBx (0lt, xlt, 0.5, A = Ga, Ge, Sn, B = Mg, Al, Si, P, Mn, Ni, Cu, Zn, As, Ru, Ag, Cd, In, Sb, Os, Au, Hg, T1, Pb) or (Mn1-pCrp) 3GaqGerSn1-q-r (0lt, plt, 0.5, 0lt, qlt, 1, 0lt, rlt, 1, 0lt, q + r < = 1), and an insulator layer laminated on the surface of the antiferromagnetic layer. It is preferable that A is Ga and / or Sn. In addition, it is preferable that B is at least one of Mg, Al, Si, Mn, Cu, Zn, Ag, Cd, In, Sb, Au, and Tl.

The invention relates to a face-centered cubic antiferromagnetic gamma-CoMn alloy single crystal film and a preparation method thereof, and belongs to the technical field of condensed state physical materials. The face-centered cubic antiferromagnetic gamma-CoMn alloy single crystal film comprises a substrate, a buffer layer and a gamma-CoMn alloy single crystal film which are sequentially arranged from bottom to top, the chemical composition of the gamma-CoMn alloy single crystal film is gamma-Co1-xMnx, wherein x is greater than or equal to 50 and less than or equal to 70. The invention further provides a preparation method of the antiferromagnetic gamma-CoMn alloy single crystal thin film. The antiferromagnetic gamma-CoMn alloy single crystal thin film is of a face-centered cubic phase, the epitaxial relationship between the gamma-CoMn alloy single crystal thin film and a substrate is CoMn (111) [10] Si (111) [11] and CoMn (111) [10] Si (111) [11] coexisting twin crystal growth, and the antiferromagnetic gamma-CoMn alloy single crystal thin film has atomic-level surface flatness, good single crystal epitaxial orientation and antiferromagnetism, is suitable for subsequent scientific research, and has good application prospects. The material is an excellent material applied to antiferromagnetic electronic devices.

The present invention relates to the field of magnetic perovskite materials. Sulfide perovskites have advantages such as high stability and good carrier transport characteristics. By appropriate doping or alloying with magnetic ions, they can become dilute magnetic semiconductors, showing both semiconductor and magnetic characteristics. However, doping and alloying are prone to problems such as phase separation. To solve the above problems, the present invention discloses a sulfide perovskite material with antiferromagnetic properties and its preparation method, including the following steps: weighing raw materials HfS2 and EuS in a molar ratio of 1:1; grinding, mixing, and pressing the above raw materials into flakes; carrying out a solid-state reaction on the above flake mixture in a CS2 protection atmosphere at 1300 °C for 6 hours to obtain a single pure-phase EuHfS3 sulfide perovskite material. This material exhibits good crystallinity, unique antiferromagnetic characteristics, and high conductivity, and can be widely applied in magnetic storage and spintronic devices.

The invention provides an anisotropic conductive film and a conductive connector which can realize low resistance, improvement of high-frequency characteristics, high resolution, improvement of contact stability caused by reduction of contact pressure, high current and improvement of durability compared with the prior art. The anisotropic conductive film (110) is provided with: an insulating film (112) comprising an elastic polymer material; and particles (200) which are dispersed in the insulating film (112) and which have magnetic anisotropy such that the easy magnetization direction becomes the thickness direction thereof, and which comprise a substance having topological antiferromagnetic properties. The particles (200) form a plurality of conductive parts (114) which are arranged at intervals in the in-plane direction of the insulating film (100) and are capable of conducting in the thickness direction thereof, and each of the conductive parts (114) is formed of a single particle (or a plurality of particles arranged in the thickness direction). Each of the particles (200) has a south pole region (604) and a north pole region (602) formed at both end portions in a direction along the easy magnetization direction, respectively, and the magnetic flux of the virtual magnetic field is concentrated in the south pole region (604) and the north pole region (602).

The invention belongs to the field of environmental monitoring, and discloses a preparation method of a nickel-based electrode with a spin pinning effect and application of the nickel-based electrode in chemical oxygen demand detection. A nickel substrate is subjected to ultrasonic treatment through hydrochloric acid and an organic solvent, cleaned and dried, a precursor layer is formed on the surface of the nickel substrate through an electro-deposition method or a hydrothermal method or an impregnation method, the precursor layer is converted into an antiferromagnetic or paramagnetic metal oxide layer through oxidation treatment, and the electrode with the spin pinning effect is prepared. The electrode is used as a working electrode in COD detection, under the action of an external magnetic field, a three-electrode system is used for electrochemical detection, and rapid and accurate determination of COD in a water body is realized. The preparation method of the nickel-based electrode with the spin pinning effect has the advantages of being simple and easy to operate and suitable for large-scale production, the stability and sensitivity of COD detection are further improved, and an efficient and reliable novel method is provided for water COD detection.

The invention discloses an antiferromagnetic metal single crystal with a three-dimensional stacking ordered structure and a preparation method of the antiferromagnetic metal single crystal. The preparation method comprises the following steps: uniformly mixing Fe powder, Co powder, Ge powder and Te powder, and then loading the mixture into a quartz tube together with a transport agent; putting the sealed quartz tube into a double-temperature-zone tubular furnace for calcining to obtain the antiferromagnetic metal single crystal; a unit cell of the antiferromagnetic metal single crystal is formed by stacking a plurality of layer structures layer by layer, and each layer structure is provided with two Te layers, a Ge layer and a Fe / Co layer, wherein the Ge layer and the Fe / Co layer are respectively positioned between the two Te layers; the plurality of layer structures are grouped in pairs to form a plurality of layer groups which are sequentially stacked, the two layer structures in the same layer group are in an AA stacking mode, and the two layer structures in the two adjacent layer groups are in an ordered staggered stacking mode. The antiferromagnetic metal single crystal has the characteristics of good cruising antiferromagnetism, neel temperature higher than room temperature, three-dimensional stacking ordered structure and the like, and promotes the development of related fields.

The application belongs to the technical field of multiferroic materials, and relates to a design method of a multiferroic material based on a vanadium-doped two-dimensional ferroelectric body and the multiferroic material. Single-layer NbOI2 primitive cells are expanded in different directions to obtain supercells of different sizes. Vanadium is used as a doping element to dope the supercells of different sizes, and the doping configurations of each supercell under different doping concentrations are obtained. The doping configuration with the lowest total energy of the ferromagnetic state and the antiferromagnetic state under each doping concentration is used as the ground state configuration of the doping concentration. The band gap Eg and the spontaneous ferroelectric polarization intensity along the b-axis of the ground state configuration under different doping concentrations are calculated. A double-Y-axis curve graph is drawn with the doping concentration as the horizontal coordinate and the spontaneous ferroelectric polarization intensity and the band gap Eg as the vertical coordinate, and the multiferroic phase region and the magnetic semimetal phase region are divided. The doping concentration-physical property evolution phase diagram is obtained, so that the corresponding doping concentration value range of the ground state configuration with the multiferroic phase of ferroelectricity and antiferromagnetism is obtained to design the multiferroic material.

The invention belongs to the technical field of magnesium alloy surface composite coatings, and particularly relates to a magnesium alloy surface non-magnetic iron-manganese collagen chitosan composite coating. The composite coating comprises a FeMn coating and a CaP / Col-CS coating, the FeMn coating is attached to the magnesium alloy substrate, and the CaP / Col-CS coating is attached to the FeMn coating. The preparation method comprises the following steps: preparing a FeMn coating on a clean and dry magnesium alloy substrate; and then a CaP coating and a Col-CS coating are prepared through a chemical conversion method. The polymer composite coating obtained by the invention not only has excellent corrosion resistance, but also can keep excellent biocompatibility; and meanwhile, the composite material also has antiferromagnetism and excellent mechanical properties which are necessary under an imaging monitoring condition. The structural design is reasonable, the preparation process is simple and controllable, the performance of the obtained product is excellent, and industrial application is facilitated.

The invention discloses a nanocrystal antiferromagnetic material, a preparation method and application, the nanocrystal antiferromagnetic material is a cobalt-nickel-silicon (Co-Ni-Si) ternary polycrystalline material, the chemical components of the nanocrystal antiferromagnetic material comprise three elements of cobalt (Co), nickel (Ni) and silicon (Si), and the atomic number ratio of cobalt to nickel to silicon is (33 + / -1): (21 + / -1): (46 + / -1). The preparation method comprises the following steps: (1) burdening; (2) packaging; (3) chemical vapor transport reaction; and (4) sampling. The antiferromagnetic material is widely applied to preparation of spintronics devices, such as magnetic tunnel junctions, spin valves, magnetic random access memories and magnetic sensors; the material is used as an antiferromagnetic pinning layer, a reference layer or an antiferromagnetic-based active layer in spintronics devices.

A magnetic memory device is provided. The device includes: a first magnetic tunnel junction pattern on a first region of a substrate and a second magnetic tunnel junction pattern on a second region of the substrate. The first magnetic tunnel junction pattern includes a first fixed magnetic structure, a first free magnetic structure, and a first tunnel barrier pattern between the first fixed magnetic structure and the first free magnetic structure. The second magnetic tunnel junction pattern includes a second fixed magnetic structure, a second free magnetic structure, a second tunnel barrier pattern, and a multiferroic pattern. The second tunnel barrier pattern is between the second fixed magnetic structure and the second free magnetic structure. The second free magnetic structure is between the second tunnel barrier pattern and the multiferroic pattern. The multiferroic pattern has ferroelectricity and antiferromagnetism, and is selectively provided to the second magnetic tunnel junction pattern.

In a method for manufacturing a magnetic laminate, a laminated film (601) having a ferromagnetic layer (631) and an antiferromagnetic layer (66) is formed, the ferromagnetic layer (631) and the antiferromagnetic layer (66) being in contact with each other in a first direction (Z) (step S1). Next, a magnetic field in the first direction (Z) is applied to the laminated film (601), and a magnetization-fixed layer (63), the magnetization direction of which is fixed with respect to the external magnetic field, is produced from the ferromagnetic layer (631) (step S2). After the application of the magnetic field is stopped, the laminated film (601) is heated at a temperature equal to or higher than the barrier temperature of the antiferromagnetic layer (66), and a magnetic laminate (6) is produced (step S3).

Disclosed are a magnon junction, magnon random access memory, microwave oscillator and detector, and electronic device. The magnon junction comprises: a first electrode layer formed by non-magnetic conductive material; a free magnetic layer arranged on the first electrode layer, formed by ferromagnetic conductive material; an antiferromagnetic barrier layer arranged on the free magnetic layer, formed by antiferromagnetic insulator material; a reference magnetic layer arranged on the antiferromagnetic barrier layer, formed by ferromagnetic conductive material; and a second electrode layer arranged on the reference magnetic layer, formed by non-magnetic conductive material. The reference magnetic layer has perpendicular magnetic anisotropy or perpendicular magnetic moment component, moment direction of which is fixed along a vertical direction; the free magnetic layer has perpendicular magnetic anisotropy or a perpendicular magnetic moment component, moment direction of which is flippable along the perpendicular direction; the antiferromagnetic barrier layer has perpendicular magnetic anisotropy or perpendicular magnetic moment component.

In order to reduce the amount of rare earth metals used in a cold storage material for a cryogenic refrigerator, this cold storage material for a cryogenic refrigerator contains crystals of Mn(Nb1-xTax)2O6 (0 ≤ x ≤ 1). In the temperature range of 6K or lower, Mn(Nb1-xTax)2O6 is antiferromagnetic, and the volume specific heat, which is a specific heat per volume, is greater than the volume specific heat of lead.

This magnetic sensor is provided with an MR element disposed on an inclined surface, and a magnetic field generator. The magnetic field generator includes a ferromagnetic portion formed of a ferromagnetic material, and an antiferromagnetic portion formed of an antiferromagnetic material and exchange-coupled with the ferromagnetic portion. The ferromagnetic portion and the antiferromagnetic portion are stacked in a direction intersecting the inclined surface. At any point on the inclined surface, the angle formed by the inclined surface and the upper surface of the substrate changes according to the position of any point in the direction perpendicular to the upper surface of the substrate.

A magnetic sensor element (100) for determining a magnetic field includes a substrate (10), a heavy metal layer (12) laminated on the substrate (10), an antiferromagnetic layer (14) laminated on the heavy metal layer (12) and composed of a first antiferromagnetic (e.g., Mn3Sn) having an antiferromagnetic magnetic structure in which time reversal symmetry has been macroscopically broken, and a cap layer (16) laminated on the antiferromagnetic layer (14). In the heavy metal layer (12), when an electric current (I) flows in an in-plane direction, a spin current is generated in a direction perpendicular to the plane, and a spin orbit moment generated by the spin current acts on a magnetic sequence of a first antiferromagnetic body of the antiferromagnetic layer (14), thereby controlling the magnetic sequence. The read signal of the first antiferromagnetic body of the antiferromagnetic layer (14) is linearly responsive to the magnetic field within a predetermined magnetic field range including a zero magnetic field.

This magnetic sensor is provided with an insulating layer, and an MR element and a magnetic field generator which are arranged on the insulating layer. The magnetic field generating body includes a ferromagnetic part made of a ferromagnetic material having a positive magnetostrictive constant, and an antiferromagnetic part made of an antiferromagnetic material and exchange-coupled with the ferromagnetic part. The MR element and the magnetic field generating body are arranged in a first direction. The insulating layer and the magnetic field generating body are configured such that, when compressive stress in the second direction is applied to the insulating layer, compressive stress in a third direction orthogonal to the first direction and intersecting the second direction is applied to the magnetic field generating body.

A quantum transducer includes a three-dimensional cavity resonator; a stack disposed in the three-dimensional cavity resonator, including a nonmagnetic first insulator film and a ferromagnetic or antiferromagnetic second insulator film that are stacked on each other, and having an interface between the first insulator film and the second insulator film; a magnetic field applicator configured to apply, to the stack, a magnetic field having a component perpendicular to the interface; and a microwave transceiver configured to transmit and receive a microwave to and from the stack. The first insulator film and the second insulator film do not include a topological insulator. The second insulator film has an easy axis of magnetization along a first axis that is perpendicular to the interface. Laser light is emitted to the stack from a direction inclined with respect to the first axis.

The present invention discloses a method for synthesizing and changing the magnetic properties of PrFeO3 rare-earth ferrite. First, praseodymium nitrate and iron nitrate are used as the ion sources of Pr and Fe, and samples are weighed and prepared according to the chemical stoichiometry of PrFeO3. The samples are dissolved in deionized water, and citric acid is added after stirring evenly. Then, the solution is titrated to neutral with ammonia water. The neutral solution is stirred and dried in a constant-temperature water bath to obtain a wet gel. The wet gel is dried and then subjected to a self-propagating reaction on an electric resistance furnace to obtain a precursor powder. The precursor powder is ground and then annealed in a muffle furnace at 800 °C to obtain an antiferromagnetic PrFeO3 rare-earth ferrite material. Finally, it is annealed at 1300 °C to obtain a PrFeO3 rare-earth ferrite magnetic material. The samples prepared by annealing at a low temperature for a short time are in an antiferromagnetic state. The present invention makes the grains and magnetic domains larger by increasing the temperature and prolonging the time, thereby changing the change of the PrFeO3 sample from antiferromagnetism to ferromagnetism.

To provide a magnetic sensor and a magnetic measuring method capable of measuring a small magnetic field with high accuracy.SOLUTION: A magnetic sensor 1 comprises a variable magnetic field detection unit 100a including a first magnetic material 31 magnetized by a measured magnetic field in a first direction (X direction), a magnetic detection element 10a which is located nearer to an X1 side than a first end part 311 on one side (X1 side) in the first direction of the first magnetic material 31 and has a sensitivity axis along the first direction, a magnetic state variable member 40 which is located nearer to the X1 side than the first end part 311 of the first magnetic material 31 and can enter a first state and a second state with different magnetic states including at least one of effective magnetic permeability and the direction of magnetization, and a magnetic state modulation member 20 for changing the magnetic state of the magnetic state variable member 40. The magnetic state modulation member 20 has an antiferromagnetism part including antiferromagnetism, and magnetization of the magnetic state variable member 40 in the first state or the second state is influenced by exchange coupling of the antiferromagnetism part and the magnetic state variable member 40.SELECTED DRAWING: Figure 1

The magnetic sensor includes a non-magnetic substrate and a sensing element 31. The sensing element 31 has a long-side direction and a short-side direction, has uniaxial magnetic anisotropy in a direction intersecting the long-side direction, and senses a magnetic field through the magneto-impedance effect. The sensing element 31 includes a plurality of soft magnetic layers 105a to 105d, and a plurality of non-magnetic layers 106a to 106c formed of a non-magnetic material and laminated between the plurality of soft magnetic layers 105a to 105d. The soft magnetic layers 105a to 105d facing each other with the respective non-magnetic layers 106a to 106c interposed therebetween are antiferromagnetically coupled.

The magnetic sensor includes a first MR element, a second MR element, a first magnetic field generator, and a second magnetic field generator. Each of the first magnetic field generating body and the second magnetic field generating body includes a ferromagnetic part and an antiferromagnetic part that is exchange-coupled to the ferromagnetic part. The first magnetic field generator is configured so as to generate a first magnetic field including a first component in a first direction, and to apply the first component to the first MR element. The second magnetic field generator is configured so as to generate a second magnetic field including a second component in the second direction, and to apply the second component to the first MR element.