77results about How to "Good magnetic stability" patented technology

A high moment bilayer first pole piece layer of a write head has high magnetic stability for promoting read signal symmetry of a read sensor of a read head. The bilayer first pole piece layer has a first layer of nickel iron and a second layer of iron nitride. The iron nitride has a high magnetic moment for conducting more flux per volume than the nickel iron first layer. In a first aspect of the invention, the nickel iron first layer is highly stabilized by providing it with a negative magnetostriction so that a stress induced anisotropy (HK) supports an intrinsic uniaxial anisotropy (HK) of the nickel iron first layer. The iron nitride second layer is formed directly on the nickel iron first layer so that by magnetic coupling the iron nitride second layer has significantly improved magnetic stability. In a second aspect of the invention the iron nitride second layer is provided with a positive magnetostriction which still further increases the magnetic stability of the bilayer first pole piece layer. In a preferred embodiment a net magnetostriction is zero or near zero. Each aspect of the invention improves the asymmetry sigma of the read head.

A GMR sensor having improved longitudinal biasing is provided as is a method of forming it. The improved biasing is provided by longitudinal biasing structures in which a soft magnetic layer is interposed between a hard magnetic biasing layer and the lateral edge of the GMR sensor element. The soft magnetic layer eliminates the need for a seed layer directly between the hard magnetic layer and the GMR element and provides improved coupling to the free layer of the GMR element and a substantial reduction in random domain variations.

The invention provides an NdFeB magnet which comprises, by mass, 29% to 33% of Pr-Nd, 0.97% to 1.5% of B, 0.4% to 0.6% of Dy, 0.2% to 0.8% of Al, 0.6% to 0.8% of Co, 0.01% to 0.5% of Cu, 0.01% to 0.2% of Zr and the balance Fe. The invention further discloses a preparation method of the NdFeB magnet. The method includes the steps that firstly, Pr-Nd alloy, Zr-Fe alloy, B-Fe alloy, Dy-Fe alloy, aluminum, cobalt, copper and iron are molten to prepare an NdFeB cast ingot; secondly, the obtained NdFeB cast ingot is milled into NdFeB powder; finally, the NdFeB powder is sintered into the NdFeB magnet. The NdFeB magnet prepared through the method has a more refined magnet grain size and higher magnet stability.

The invention relates to a material preparation method capable of improving direct current biasing characteristic. The material preparation method is characterized by comprising the following steps: (1) sieving Fe-Si-Al magnetic powder by adopting a sieve with 140 meshes, thus obtaining a first kind of Fe-Si-Al magnetic powder; sieving the Fe-Si-Al magnetic power by adopting a sieve with 300 meshes, thus obtaining a second kind of Fe-Si-Al magnetic powder; (2) mixing the first kind of Fe-Si-Al magnetic powder and the second kind of Fe-Si-Al magnetic powder in a mass ratio of 1.5:4 to obtain amixed powder material, putting the mixed powder material into a ball mill, and carrying out ball milling for 0.25-2.0 hours; and (3) insulating and coating, thus obtaining the coated magnetic powder.The magnetic powder material is simple in preparation technology, environmentally friendly, and the direct current biasing characteristic of the prepared magnetic powder core can be improved.

The invention relates to quantum ceramic and a formulation, a making method and application thereof and relates to the field of materials. The formulation of the quantum ceramic comprises tourmaline, meteorite, stone needle, medical stone, germanite, silicon dioxide, titanium dioxide, calcium oxide, kaolin, iron sesquioxide, zinc oxide, neodymium, boron and magnesium oxide and is reasonable in proportioning, so that performance of the quantum ceramic which is finally obtained is improved effectively. The making method includes: mixing raw materials according to the above formulation; sintering and then cooling in a nitrogen atmosphere. The making method is simple to operate and convenient for industrial production. The quantum ceramic made by the method releases micro magnetism and infrared light waves, thereby having excellent healthcare efficacy. By applying the quantum ceramic in accessories, functionality of the accessories can be improved effectively, and value of the accessories can be increased.

A high-frequency magnetic material is provided and includes: an oxide phase including: a first oxide of a first element being at least one selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, a rare-earth element, Ba, and Sr, and a second oxide of a second element being at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, and Zn, the first oxide and at least a part of the second oxide being formed into a solid solution; and magnetic metal particles including at least one of Fe and Co and having a particle size of 1 to 100 nm, the magnetic metal particles being deposited on a surface and inside of the oxide phase, the magnetic metal particles occupying 50% of a volume of the high-frequency magnetic material exclusive of a void.

Embodiments of the invention provide a spin-valve type magnetic head that satisfies the requirements of both high read output and stability with narrow tracks. In one embodiment, a domain control film is formed on a magnetoresistive layered film in the same track width. A double closed flux path structure that uses three magnetic layers is employed with magnetic coupled structure in both ends of the track. The three magnetic layers are a soft magnetic free layer, a domain-stabilization ferromagnetic layer, and a soft magnetic anti-parallel layer.

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.

A magnetoresistive sensor having a magnetic anisotropy induced in one or both of the free layer and/or pinned layer. The magnetic anisotropy is induced by a surface texture formed in the surface of the magnetic layer of either or both of the free layer or pinned layer. The surface texture is formed by a direct, angled ion mill performed on the surface of the magnetic layer while holding the wafer on a stationary chuck. By applying this ion milling technique, the magnetic anisotropy of the pinned layer can be formed in a first direction (eg. perpendicular to the ABS) while the magnetic anisotropy of the free layer can be formed perpendicular to that of the pinned layer (eg. parallel to the ABS).

A magnetomechanical marker for use in an electronic article surveillance system comprising a magnetomechanical element, a bias magnet and a housing. The magnetomechanical element comprises first and second resonator strips composed of an unannealed magnetostrictive amorphous metal alloy having a resonant frequency response including a resonant frequency minimum in response to the incidence thereon of an electromagnetic interrogating field. The bias magnet has a bias point to magnetically bias the magnetomechanical element so that the magnetomechanical element resonates at a predetermined frequency in the presence of an electromagnetic interrogating field. The housing has a cavity sized and shaped to accommodate the first and second resonator strips positioned in the cavity in registration and to allow the first and second resonator strips to mechanically vibrate, wherein the first resonator strip has a first weight and first shape and is positioned proximate the second resonator strip so that the first weight and the first shape mechanically interfere with the second resonator strip to impart a stress on the second resonator strip which shifts the resonant frequency minimum to the bias point.

The invention relates to the technical field of cell separation and purification materials and particularly relates to compound immune magnetic beads for separation and purification of hepatic stellate cells and a preparation method of the compound immune magnetic beads. The compound immune magnetic beads are prepared by grafting antibodies on magnetic bead granules of which the granule sizes are50-1500nm, wherein the antibodies include CD11b and CD146 antibodies, and the inner cores of the magnetic bead granules are Fe3O4 micro-spheres including carboxylated graphene layers, modified chitosan layers and sodium alginate layers from inside to outside. The antibodies are grafted on the magnetic bead granules to obtain the compound immune magnetic beads; the magnetic bead granules contain more carboxyl functional groups, have good dispersion properties in solutions and can not aggregate easily; the antibodies have a higher grafting ratio on the magnetic bead granules and have higher binding stability; and the compound immune magnetic beads can be used for separation and purification of hepatic stellate cells so as to obtain hepatic stellate cells with higher purity and better activity.

A spin-valve type magnetoresistive sensor with a bias structure enabling a magnetization direction of a free magnetic layer to be uniformly arranged with certainty. The spin-valve type magnetoresistive sensor comprises an antiferromagnetic layer; a pinned magnetic layer having a magnetization direction made stationary; a nonmagnetic electrically conductive layer formed between the pinned magnetic layer and a free magnetic layer; soft magnetic layers that are arranged on the free magnetic layer while a spacing corresponding to a track width is left between the soft magnetic layers and that fill recesses in the free magnetic layer on both sides of an area corresponding to the track width; bias layers formed on the soft magnetic layers; and electrically conductive layers. The antiferromagnetic layer and the bias layers are each made of an alloy containing at least one or more elements selected from among Pt, Pd, Rh, Ru, Ir, Os, Au, Ag, Cr, Ni, Ne, Ar, Xe and Kr, as well as Mn.

The invention provides a planarization method of a magnetic tunnel junction. The magnetic tunnel junction comprises an amorphous iron-cobalt-boron layer. The method is characterized in that the methodcomprises the step that ion or plasma beams are adopted to bombard the amorphous iron-cobalt-boron layer. According to the planarization method of the invention, low-power ion or plasma beam bombardment is adopted, so that surface atoms can acquire a certain kinetic energy but cannot escape, and therefore, a material can be shifted from rough protrusions to troughs, and an MTJ (magnetic tunnel junction) multilayer film deposition of atomic-level smoothness can be obtained.

A precursor for a Nb₃Sn superconductor wire to be manufactured by the internal diffusion method. The precursor includes Nb-based single core wires, Sn-based single core wires, and a cylindrical diffusion barrier made of Ta or Nb. Each Nb-based single core wire includes a Nb-based core coated with a Cu-based coating made of a Cu-based matrix. Each Sn-based single core wire includes a Sn-based core coated with a Cu-based coating made of a Cu-based matrix. The Nb-based single core wires and the Sn-based single core wires are regularly disposed in the diffusion barrier. The Nb-based single core wires includes at least two kinds of Nb-based single core wires having different Cu/Nb ratios and the Cu/Nb ratio is a cross sectional area ratio of the Cu-based coating to the Nb-based core.

The invention discloses a magnetic ultrasonic wave on-line scale-preventing-removing all-in-one machine which comprises a high-intensity transducer, a high-intensity transducer shielding protecting cover, strong magnets, strong magnet protecting devices and an ultrasonic wave generator. The high-intensity transducer is arranged in the high-intensity transducer shielding protecting cover and is connected with the ultrasonic wave generator through an electric cable. The bottom end of the high-intensity transducer extends out of the high-intensity transducer shielding protecting cover and is in contact with the surface of a metal pipeline. The strong magnets are arranged on the bottom of the high-intensity transducer shielding protecting cover and are placed on the two sides of the bottom of the high-intensity transducer. The strong magnet protecting devices are arranged on the surfaces of the strong magnets. The high-intensity transducer and the strong magnets are combined, ultrasonic pulse resonance waves generated by the high-intensity transducer and a magnetic field generated by the strong magnets have effect on a metal pipeline, synergistic effect is formed, wave-like impact waves are generated, a scale layer of the pipe wall of the metal pipeline is impacted and hammered ceaselessly, stress is generated between scale layer molecules, so that scale layer fracturing, loosening and falling off happen, and the scale layer sinks deep into an impounding reservoir with water flow.