53 results about "Anisotropy energy" patented technology

The invention discloses a hydrophobic surface, a preparation method and application thereof in dropwise condensation heat transfer, and relates to the fields of micro-nano manufacturing, condensation heat transfer and the like. The hydrophobic surface has a micro-nano two-level structure, wherein the micro-nano two-level structure is anisotropic and the hydrophobic surface has anisotropic wettability. On one hand, the micro-nano two-level structure of the hydrophobic surface can promote realization of dropwise condensation, and can significantly improve the heat transfer efficiency compared with the common filmwise condensation,; on the other hand, the anisotropic wettability of the hydrophobic surface can affect condensation and fall of water drops to a certain extent and can accelerate discharge of liquid drops under the influence of gravity and other factors, thereby further improving the condensation heat transfer efficiency.

A memory cell (310) for a magnetic memory device (300) includes a free layer (311), a cap layer, an antiferromagnetic layer, and a synthetic antiferromagnetic layer which comprises two or more than two ferromagnetic layers that are antiferromagnetically coupled through non-magnetic space layers. The synthetic antiferromagnetic layer is pinned by antiferromagnetic layer. The antiferromagnetic layer and the synthetic antiferromagnetic layer form a synthetic antiferromagnetic pinned (SAFP) recording layer. The magnetization of the SAFP recording layer can be changed by combining a heating process and an external field induced from currents flowing along the bit line (320) and the word line (330). Therefore, a MRAM with high density, high thermal stability, low power dissipation and high heat tolerance can be achieved after introducing the SAFP recording layer due to the high volume and anisotropy energy of the SAFP recording layer.

The invention provides a magnetic element, a memory system and a write operation method thereof. The magnetic element comprises a magnetic fixation layer, a non-magnetic isolation layer, a magnetic free layer and a cover layer. The non-magnetic isolation layer is arranged between the magnetic fixation layer and the magnetic free layer. The cover layer connects the magnetic free layer and an external semiconductor transistor circuit. The magnetic free layer has demagnetizing energy perpendicular to the membrane plane direction and anisotropy energy perpendicular to anisotropy. The anisotropy energy perpendicular to anisotropy is lower than the demagnetizing energy perpendicular to the membrane plane direction. When the write current flows through the magnetic element, the magnetic free layer can be switched between parallel and anti-parallel magnetic states in the plane direction to achieve the purpose of magnetic storage under a spin torque transmission effect.

The invention discloses a magnetic component for achieving spinning torque transfer switching, a fabrication method of the magnetic component and the magnetic storage device. The magnetic component comprises a dual-pin perpendicular anisotropy magnetic fixed layer, non-magnetic spacing layers and a perpendicular anisotropy magnetic free layer, wherein the perpendicular anisotropy magnetic free layer is arranged between the dual non-magnetic spacing layers and is provided with demagnetization energy and anisotropy energy, the demagnetization energy is perpendicular to a film plane direction, the anisotropy energy is correspondingly perpendicular to anisotropy, and the perpendicular anisotropy energy is larger than the demagnetization energy perpendicular to the film plane direction. When a writing current passes through the magnetic component, the perpendicular anisotropy magnetic free layer can be switched between a parallel magnetic state perpendicular to a plane direction and a reverse parallel magnetic state by a spinning torque transfer effect so as to achieve the purpose of magnetic storage.

The invention belongs to the technical field of magnetic refrigerating materials and particularly relates to a method for preparing polymer-bonded magnetic refrigerating composite material, which is characterized in that room-temperature magnetic refrigerating alloy particles including iron-based, manganese-based, nickel-based or gadolinium-based particles are mechanically mixed with a resin with high thermal conductivity, and a polymer is cured in magnetic field to obtain the oriented arrangement with alloy particle embedded, wherein alloy particles account for 50-98% of the total volume. The magnetic refrigerating composite block material has high magneto-thermal performance, large magneto-crystalline anisotropy and large magneto-thermal anisotropy and also has low vortex loss when being used at high frequency. The compressive toughness of the magnetic refrigerating composite block material is improved by 1 to 2 orders of magnitude than that of the existing magnetic refrigerating alloy. The process for preparing the polymer-bonded magnetic refrigerating composite material is simple, the complex profiles in near net shapes can be obtained, the steps of cutting and processing are omitted, and industrial mass production is easy to realize.

A method of using a magnetostrictive material to achieve a high magnetomechanical coupling factor comprising building an internal anisotropy energy into the magnetostrictive material and applying a tensile or compressive stress to the magnetostrictive material with the built-in internal anisotropy energy. The internal anisotropy energy is built into the magnetostrictive material by annealing the magnetostrictive material under an annealing stress or a suitable magnetic field. For a positive magnetostrictive material, when the annealing stress is compressive, the stress applied to the annealed material under operation is tensile, and when the annealing stress is the tensile, the stress applied to the annealed material under operation is compressive. For a negative magnetostrictive material, when the annealing stress is compressive, the stress applied to the annealed material under operation is tensile, and when the annealing stress is tensile, the stress applied to the annealed material under operation is compressive.

Magneto-elastic amorphous alloy material and a preparation method thereof are provided. The material is composed of FexReyBz, wherein, Re is one or more than two of La, Sm, Tb, Dy and Y. The preparation method is to mix and melt the FexReyBz into master alloy according to the atom percentage, produce amorphous wires on self-developed wire spraying equipment, strengthen internal stress through drawing the wires and improve the magneto-elastic performance of the wires. The material is provided with the 10<-3> vertical large magnetostrictive coefficient. And through the quenching and rapid setting preparation method, extremely large inner stress gradient from the surface to the core of the wires is made. The material is also provided with large inner stress anisotropy performance, and part of magneto-elastic performance is produced. The surface crystallization layer of the wires, the thickness of which is tens of nanometers to hundreds of nanometers, and amorphous matrixes produce magnetocrystalline anistotropy energies which strengthen the magneto-elastic performance of the wires. The material is provided with the vertical large magnetostrictive coefficient and makes use of a self-developed displacement sensor and a measurement instrument. Compared with the present import super-magnetostrictive displacement sensor, the sensor has the advantages of large investigation depth, high precision and strong vibration resistance capacity.

The invention provides a perpendicular anisotropic magnetic element, a preparation method and a magnetic memory. A semiconductor integrated circuit is connected by the magnetic element in a magnetic device to form a storage bit cell; the magnetic element has a structure of a perpendicular anisotropic magnetic pinned layer, a non-magnetic spacer layer and a perpendicular anisotropic magnetic free layer; the non-magnetic spacer layer is located between the perpendicular anisotropic magnetic pinned layer and the free layer; the perpendicular anisotropic magnetic free layer has demagnetizing energy perpendicular to the membrane plane direction and corresponding perpendicular anisotropic energy; the perpendicular anisotropic energy is greater than the demagnetizing energy perpendicular to the membrane plane direction; and when write current passes through the magnetic element, the perpendicular anisotropic magnetic free layer can achieve switching between a parallel magnetic state and an anti-parallel magnetic state perpendicular to the plane direction through a spin torque transmission effect, so that the target of magnetic storage is achieved.

A magnetic recording apparatus includes a magnetic recording medium that is provided with a first magnetic layer with magneto crystalline anisotropy energy, a second magnetic layer with magneto crystalline anisotropy energy that is smaller than the magneto crystalline anisotropy energy of the first magnetic layer, and a nonmagnetic metal layer that is positioned between the first magnetic layer and the second magnetic layer and that provides coupling force between the first magnetic layer and the second magnetic layer; and a magnetic head that includes a main pole that applies a recording magnetic field in a direction perpendicular to a film surface of the magnetic recording medium to the magnetic recording medium, and an alternate current (AC) magnetic field generator that applies an AC magnetic field with a frequency of 1-40 GHz to the magnetic recording medium.

The invention discloses a regulation and control method of a tunneling magnetoresistance sensor. The regulation and control method comprises the steps that a voltage is loaded between a bottom electrode and a top electrode of the tunneling magnetoresistance sensor, wherein the voltage is a variable voltage provided by an adjustable power supply; and the voltage value between the bottom electrode and the top electrode is adjusted to adjust and control the range and sensitivity of the tunneling magnetoresistance sensor. According to the regulation and control method, the voltage is loaded between the bottom electrode and the top electrode of the tunneling magnetoresistance sensor based on the adjustable power supply, and the coupling coefficient of the interface vertical anisotropy of the magnetic tunnel junction in the tunneling magnetoresistance sensor is changed by adjusting the applied voltage value; and through the coupling coefficient, the interface vertical anisotropy energy can be adjusted, and then the magnetic anisotropy energy of the magnetic tunnel junction is adjusted, so that the sensitivity and the linear region of the tunneling magnetoresistance sensor are correspondingly adjusted, no additional compensation circuit is needed, and the overall complexity of a magnetic detection system is reduced. Correspondingly, the invention further discloses a regulation and control system of the tunneling magnetoresistance sensor.

The invention relates to a novel stress sensor based on a magnetoresistance effect. The technical scheme is as follows: an upper layer of the novel stress sensor is an upper ferromagnetic layer; a middle layer is a non-ferromagnetic layer; a lower layer is a lower ferromagnetic layer; a packing layer packs the upper layer, the middle layer and the lower layer; a wire is connected with the upper ferromagnetic layer after passing through the packing layer; the other end of the wire is connected in series to an indicator light, an ampere meter and a power supply and is then connected with the lower ferromagnetic layer after passing through the packing layer; and magnetostriction coefficients of the upper ferromagnetic layer and the lower ferromagnetic layer have opposite symbols, and the magnetostriction coefficients are big and have the same small anisotropic index. The novel stress sensor based on the magnetoresistance effect overcomes the defects of poor sensitivity to an external environment, poor fatigue resistance, complex structure, difficult miniaturization, high cost, poor sensitivity and accuracy of the traditional stress sensor which cannot meet the demands. The novel stress sensor based on the magnetoresistance effect has the advantages of simplicity in circuit design, mature process and sensitivity and can quantify scales directly.

A magnetic recording device which can write magnetic information with high density. The device uses, for a magnetic recording layer of a magnetic recording medium, a magnetic material whose anisotropy energy varies with an applied electric field. The head has an electrode for applying an electric field to a recording area of the magnetic recording medium. Magnetic recording is performed by applying an AC electric field from the electrode while a DC magnetic field is applied to the recording area of the magnetic recording layer.

The invention discloses a preparing method for a two-dimensional skyrmion crystal. Nanometer magnetic discs are directly put on the upper surface of a perpendicular anisotropic material, and a skyrmion crystal structure is obtained through the competition of interaction of demagnetization energy, exchange energy and anisotropic performance between magnetic materials. Especially, a cobaltic nanometer magnetic disc array is put on the plane of a cobalt and platinum alloy, and the magnetized rotating directions of all the magnetic discs of the nanometer magnetic disc array are unified through the method of applying combined magnetic fields which are parallel to the surface of a film and perpendicular to each other.

A method of generating and erasing magnetic Skyrmion by using an electric field is provided. A magnetic Skyrmion material is grown on a ferroelectric material substrate. After an electric field is applied locally, the ferroelectric material produces a strain, the anisotropic property of the magnetic material is affected, the single domain state in the region under an electrode changes from a metastable state to an unstable state, and thus, magnetic Skyrmion is generated. The generation of magnetic Skyrmion by using an electric field is characterized by low power consumption and low device heat.

The invention relates to a rapid salt-bath nitridation method by applying a magnetic field. The method comprises the following steps: washing, pre-oxidizing, melting nitridation basic salts, applying a magnetic field to carry out nitridation, and washing. The method has the advantages that under the effect of a magnetic field, domain rotation and domain wall displacement are generated around the material surface, the exchange energy and anisotropy energy are increased, and the nitrogen atom diffusion is accelerated; magnetization happens near the surface of workpiece, magneto-striction is generated then, the strain energy is increased, and the diffusion of nitrogen atom is accelerated; active nitrogen atoms diffuse on the material surface under the effect of the magnetic field, the surface adsorption and diffusion are accelerated, the penetration is promoted and accelerated, the salt-bath nitrogen penetration time is reduced, the energy is saved, and the environment is protected; the hardness and surface wear-resistant performance of a sample is improved, the excellent surface corrosion resistant performance of the sample can be preserved; in the provided method, people can obtain a nitrogen penetration layer with the same thickness as that of a nitrogen penetration layer, which is produced by a common salt-bath nitrogen penetration method, by low-temperature heating, thus the energy is saved, and the production cost is reduced.

A multicore magnetic particle. In one embodiment, the magnetic particle includes a plurality of superparmagnetic cores embedded in a non-magnetic matrix. In another embodiment, the effective anisotropy energy barrier of the particle is larger than the sum of the anisotropy energy barriers of the individual superparamagnetic cores. In yet another embodiment, the superparamagnetic cores are close enough to interact magnetically by exchange coupling and dipole interaction. In still yet another embodiment, the specific loss power of the magnetic particle is greater than the specific loss power of an equivalent mass of individual superparamagnetic cores.

A true random number generator (TRNG) device having a magnetic tunnel junction (MTJ) structure coupled to a domain wall wire. The MTJ structure is formed of a free layer (FL) and a reference layer (RL) that sandwiches a tunnel barrier layer. The free layer has anisotropy energy sufficiently low to provide stochastic fluctuation in the orientation of the magnetic state of the free layer via thermal energy. The domain wall wire is coupled to the MTJ structure. The domain wall wire has a domain wall. Movement of the domain wall tunes a probability distribution of the fluctuation in the orientation of the magnetic state of the free layer. The domain wall can be moved by application of a suitable current through the wire to tune the probability distribution of 1's and 0's generated by a readout circuit the TRNG device.

A magnetic transfer master substrate for transferring magnetic information thereof to a perpendicular recording magnetic recording medium in contact therewith under application of a magnetic field comprises a transfer surface area with a magnetic layer formed thereon in a pattern according to the magnetic information to be transferred to the perpendicular magnetic recording medium and a non-transfer surface area laying below said transfer surface area, wherein the magnetic layer has a perpendicular magnetic anisotropy of an anisotropy energy higher than 4×10⁶ erg/cm³.

The invention relates to a method for increasing the interface magnetic anisotropy energy of a ferromagnetic metal/oxide bilayer film, belonging to the technical field of high-density information storage and sensing. Chromium Cr/FeNx/MgO/Ta multilayer films were deposited on Si substrates after surface acidification. After deposition, heat treatment is carried out to promote the uniform occupationof N atoms at interstitial sites. N atom can change the coordination environment of Fe, the charge redistribution at Fe/MgO interface is caused, the energy band structure of Fe is effectively regulated, the electron occupation on a dz2 orbit is greatly increased, and the hybrid state of Fe3dz2-O2pz orbit can be regulated, so that the magnetic anisotropy energy of the interface of the thin film isremarkably increased. In the invention, only nitrogen is needed to be introduced into the process of preparing the Fe thin film, and the orbital hybridization intensity of FeO can be directly regulated and the magnetic anisotropy energy of the interface is increased. There is no need of high cost rare metal or expensive additional device, which has the characteristics of simple preparation and convenient control. With the advantages of high efficiency and low cost, the method for increasing the interface magnetic anisotropy energy of a ferromagnetic metal/oxide bilayer film is suitable for the future spintronics technology.

A magnetic recording device which can write magnetic information with high density. The device uses, for a magnetic recording layer of a magnetic recording medium, a magnetic material whose anisotropy energy varies with an applied electric field. The head has an electrode for applying an electric field to a recording area of the magnetic recording medium. Magnetic recording is performed by applying an AC electric field from the electrode while a DC magnetic field is applied to the recording area of the magnetic recording layer.

The invention discloses a method for solving a super-paramagnetic state of magnetic recording particles, which is characterized in that: a layer of anti-ferromagnetic material capable of pinning the magnetic moment thereof is wrapped outside the magnetic recording particles, and the anti-ferromagnetic material is coupled with the magnetic recording particles through an interface magnetic moment to ensure that the magnetic moments of the magnetic recording particles are arranged along the same direction. The method can overcome thermal disturbance under a nano-scale of the magnetic particles, improve uniaxial anisotropy energy of the magnetic particles artificially, and solve the problem of unstable records in the super-paramagnetic state.

The invention belongs to the field of polymer composite materials, and relates to a magnetic field induced fiber reinforced composite material used for an ultrasonic motor and a preparation method thereof. The method includes coating chopped carbon fibers with ferric ferrous oxide nanoparticles, performing dispersion in polyamide acid in-situ synthesis, allowing the carbon fibers to be orderly arranged under the function of an external magnetic field, and preparing the composite material through thermal imidization. The anisotropy of this product can endow the composite material with good impact resistance, wear resistance and other characteristics. The composite material can greatly improve the motion conversion efficiency, load bearing capacity, running stability and service lifetime ofthe ultrasonic motor.

The invention discloses low-anisotropy non-oriented silicon steel for hydroelectric power generation and a production method thereof. The low-anisotropy non-oriented silicon steel comprises the following chemical compositions: by weight percentage, 2.8-3.2% of Si, 0.1-0.3% of Mn, 0.5-0.8% of Als, 0.0010% - 0.0025% of B, 0.01% - 0.02% of Cu, no less than 80 ppm of [ S + C + N + Ti ] and the balanceFe and inevitable impurities, and a non-oriented silicon steel product with the thickness of 0.50mm is prepared by the steps of molten iron pretreatment, converter smelting, RH refining, continuous casting, hot rolling, normalized pickling, cold rolling, continuous annealing, coating and finishing, under the condition that the test density is 7.6 g/dm3, the magnetic induction B50 is greater thanor equal to 1.65T, the iron loss P1.5/50 is less than or equal to 2.40 W/kg, the iron loss anisotropy is less than 10%, and the design requirement of hydroelectric power generation equipment can be met at a high level.