Abstract: Corrosion resistance of a magnetic film composed mainly of Fe is maintained while keeping its magnetic properties. A magnetic head having a magnetic core is formed in part of the magnetic thin film, which contains not only an alloy of Fe-metalloid series but also (Al, Ru) or (Al, Rh) and which is thermally treated at a constant temperature to develop the soft magnetic properties. The deterioration of the saturation magnetization and the soft magnetic properties is suppressed by adding (Al, Ru) or (Al, Rh) together. The magnetic film has a high saturation magnetization and excellent soft magnetic properties and is excellent in corrosion resistance and hardness.
Abstract: A magnetic thin film having excellent soft magnetic properties formed by alternately laminating a main magnetic layer and an intermediate layer, in which the main magnetic layer includes magnetic crystal grains substantially having a columnar structure which have an average height dl and an average diameter ds forming a shape ratio of 0.3.ltoreq.ds/dl.ltoreq.90.9, and the intermediate layer has saturation magnetic flux density of at least 0.1 tesla less than the main magnetic layer. The main magnetic layer and the intermediate layer having saturation magnetic flux density of at least 0.1 tesla less than the main magnetic layer are alternately laminated. It is preferable that the main magnetic layer has a thickness of 3 to 100 nm, and the intermediate layer has a thickness of 0.1 to 10 nm. In addition, it is preferable that a thickness of the entire laminated structure is in the range of about 100 nm to 10 .mu.m.
Type:
Grant
Filed:
January 30, 1996
Date of Patent:
December 15, 1998
Assignee:
Matsushita Electric Industrial Co., Ltd.
Abstract: The inventive material exhibits giant magnetoresistance upon application of an external magnetic field at room temperature. The hysteresis is minimal. The inventive material has a magnetic phase formed by eutectic decomposition. The bulk material comprises a plurality of regions characterized by a) the presence of magnetic lamellae wherein the lamellae are separated by a distance smaller than the mean free path of the conduction electrons, and b) a matrix composition having nonmagnetic properties that is interposed between the lamellae within the regions. The inventive, rapidly quenched, eutectic alloys form microstructure lamellae having antiparallel antiferromagnetic coupling and give rise to GMR properties. The inventive materials made according to the inventive process yielded commercially acceptable quantities and timeframes. Annealing destroyed the microstructure lamellae and the GMR effect. Noneutectic alloys did not exhibit the antiparallel microstructure lamellae and did not possess GMR properties.
Type:
Grant
Filed:
September 1, 1995
Date of Patent:
October 20, 1998
Assignee:
The Regents, University of California
Inventors:
Johannes J. Bernardi, Gareth Thomas, Andreas R. Huetten
Abstract: The present invention is a magnetic recording medium comprising a substrate and a magnetic layer including a binder resin and a plate-like magnetic powder of which easy axis of magnetization exists in a plane, and this magnetic recording medium is excellent in recording and regeneration characteristics.
Abstract: Aminoquinones and their use as additives in fluid media for providing corrosion resistance to metals in contact with the fluid medium and their use in preparing copolymers to provide corrosion resistant binder compositions for magnetic information storage media, the copolymers formed, the magnetic information storage media and a method for improving corrosion resistance in magnetic particles are provided.
Abstract: A granule-type magnetoresistive material is used to form a MR component, which is equipped in a magnetic head, or the like. When placing the magnetoresistive material in the external magnetic field, the electric resistance is altered responsive to a variation of the external magnetic field. In order to increase a magnetic-field sensitivity, the magnetoresistive material is composed of an alloy whose atomic composition is expressed by a chemical formula of (Co.sub.1-x Fe.sub.x).sub.y Ag.sub.1-y, where 0.45.ltoreq.x.ltoreq.0.55 and 0.24.ltoreq.y.ltoreq.0.35; or another chemical formula of (Co.sub.1-x Fe.sub.x).sub.y (Ag.sub.1-z Cu.sub.z).sub.1-y, where 0.45.ltoreq.x.ltoreq.0.55, 0.24.ltoreq.y.ltoreq.0.35 and z.ltoreq.0.14.
Abstract: A magnetic material consisting essentially of A1 and 10 to 50 at. % of at least one capable of alloying with A1 to form quasicrystals (for example, 5 to 25 at. % of at least one member selected between Cu and Pd and 5 to 35 at. % of Mn) and up to 25 at. % of at least one element having a smaller atomic radius than those of the above elements (for example, B). The magnetic material is produced by adding, to a mixture consisting of A1 and at least one element capable of alloying with A1 to form quasicrystals and including at least one transition metal, at least one element having a smaller atomic radius than those of A1 and the above elements to dissolve the element having a smaller atomic radius in a solid solution form in a quasicrystalline phase. The thus obtained magnetic crystal is useful in various applications, such as magnetic recording heads, and a process for producing the same.
Type:
Grant
Filed:
July 26, 1993
Date of Patent:
March 14, 1995
Assignees:
Tsuyoshi Masumoto, Akihisa Inoue, Yoshida Kogyo K.K.
Abstract: A semiconductor film is provided characterized by having high carrier mobility and carrier density. The semiconductor film is doped with the rare-earth element erbium so as to improve its temperature stability. The semiconductor film is thereby particularly suited for use as a magnetic field sensing device, such as a Hall effect sensor or magnetoresistor. The semiconductor film is formed from a narrow-gap Group III-V compound, preferably indium antimonide, which is n-doped with the erbium to provide an electron density sufficient to increase temperature stability. In particular, the semiconductor film is characterized by a nini-structure which is generated using a slab-doping technique. The slab-doping process encompasses the growing of alternating layers of doped and undoped layers of the Group III-V compound, with the doped layers being substantially thinner than the undoped layers, and preferably as thin as one atomic plane.
Type:
Grant
Filed:
September 28, 1992
Date of Patent:
May 24, 1994
Assignee:
General Motors Corporation
Inventors:
Joseph P. Heremans, Dale L. Partin, Christopher M. Thrush
Abstract: Ultrafine particles of Fe-Co-P material with a Fe/Co atomic ratio of from 95/5 to 70/30 and a (Fe+Co)/P atomic ratio of from 85/15 to 60/40 show improved ferromagnetic properties. The average particle size is from 0.005 to 0.1 .mu.m. Such ultrafine particles are prepared through gas phase reaction by evaporating a source material. They are useful in both magnetic and thermomagnetic recording media ensuring high density recording.
Abstract: A soft magnetic alloy film has a composition formula expressed by Fex Mz Cw. M is at least one metallic element selected from a group consisting of Ti, Zr, Hf, Nb, Ta, Mo or W, or a mixture of these metallic elements. The composition ratio of x, z and w satisfies the relation expressed by 50 atomic %.ltoreq.x.ltoreq.96 atomic %, 2 atomic %.ltoreq.z.ltoreq.30 atomic %, 0.5 atomic %.ltoreq.w.ltoreq.25 atomic %, and x+z+w=100. The metallic structure of the soft magnetic alloy film basically consists of crystal grains having an average grain size of 0.08 .mu.m or below. The metallic structure contains the crystal phase of carbide of the element M.
Abstract: The coercivity of magnetic alloys formed from platinum, cobalt, and boron is enhanced by incorporating from 12 to 14 percent of boron together with amounts of platinum and cobalt such that the ratio of platinum to cobalt is from 0.90 to 1.2. The magnetic alloy is formed by rapid solidification of a homogeneous melt, and the solidified casting is heat treated to improve microstructure and increase coercivity.
Abstract: A metal fiber having unidirectional dendritic texture which is an assembly of a group of dendrites wherein primary arms have grown at angle of within 20.degree. relative to the metal fiber axis, diameter of said fiber being not greater than 100 .mu.m. There is also disclosed a single crystalline metal fiber which is a single crystalline material throughout the entire length, diameter of said fiber being not greater than 100 .mu.m, length of said fiber being not less than 40 mm. These fibers can be produced by melt-spinning of metal.
Abstract: Magnetic energy is converted into mechanical energy by applying a changing agnetic field to a rare earth alloy of the formula Tb.sub.x Dy.sub.1-x at a temperature in the range of about 0.degree. K. to 170.degree. K., wherein x and the operating temperature are selected to minimize the basal plane anisotropy.
Type:
Grant
Filed:
June 30, 1989
Date of Patent:
March 6, 1990
Assignee:
The United States of America as represented by the Secretary of the Navy
Abstract: A die head is disclosed for use on an extruder die in which a plate-like structure having an elongated slot through which extrudate is extruded. the slot has a central area which is narrower than the height at each end of the elongated slot. The elongated slot also is arcute in shape, and the central area to each end portion is a mirror image of one another. The die head produces an extrudate which is uniform in thickness throughout a cross-section taken normal to the direction of extrusion, but the extrudate is bowed or arcuate in shape. The combination of a metallic shell and a flexible arcuate magnetic material is also disclosed in which the extruded flexible magnetic strip material is curled within the cylindrical shell such that both the peripheral exterior surface and the peripheral interior surface of the flexible magnetic material is flat in axial cross-section.
Abstract: A permanent magnetic alloy mainly composed of gold for making magnetic personal ornaments comprises 50 to 75 weight % gold, 12 to 40 weight % palladium and 3 to 15 weight % cobalt. The alloy is gold or white gold in color and can be plastically deformed to a desired shape. The 12, 14 and 18 Karat gold alloys have maximum energy products of 3.0, 2.2 and 0.9 MGOe, respectively.
Abstract: Fe-B-R type permanent magnet is produced by: forming an anticorrosive coating film layer on a Fe-B-R base permanent magnet material body by means of vapor deposition to thereby improve the corrosion resistance thereof.The anticorrosive thin film is formed of metal, oxides, nitrides, carbides, borides, silicides, composite compositions thereof, or a mixture thereof. Additionally blasting, shot peening, heat treatment for forming an interdiffusion layer, and/or resin impregnation may be applied.
Abstract: The disclosed permanent magnet has a coercive force of larger than 500 Oe, a residual magnetic flux density of larger than 5 kG, and a maximum energy product of larger than 2 MGOe, and it consisting essentially of 48.about.66.9 Atm % of iron, 33.about.47 Atm % of platinum, and 0.1.about.10 Atm % of niobium. It includes a crystal structure of an incomplete single .gamma..sub.1 phase of a face-centered tetragonal system due to either the composition thereof or heat treatment applied thereto. The permanent magnet is made by heating an alloy of the above main composition at 900.degree..about.400.degree. for one minute to ten hours and quenching the alloy at a high speed of faster than 30.degree. C./minute but slower than 2,000.degree. C./sec.
Type:
Grant
Filed:
March 22, 1988
Date of Patent:
March 21, 1989
Assignee:
The Foundation: The Research Institute of Electric and Magnetic Alloys
Abstract: A recording material made of an alloy capable of exhibiting different spectral reflectances at an equal temperature, depending on a heating-cooling cycle to which the alloy is subjected. The alloy can possess in solid state different crystal structures at a first temperature higher than the room temperature and at a second temperature lower than the first temperature but not lower than the room temperature. A part of the surface of the alloy exhibits, as a result of being quenched from the first temperature, a crystal structure which is different from the crystal structure at the second temperature, while the other part possesses the crystal structure at the second temperature, so that these two parts exhibit different spectral reflectances. Using this recording medium, it is possible to record, reproduce and erase information by means of, for example, laser beams.
Type:
Grant
Filed:
August 22, 1984
Date of Patent:
February 23, 1988
Assignee:
Hitachi, Ltd.
Inventors:
Tetsuro Minemura, Hisashi Ando, Isao Ikuta, Yoshiaki Kita
Abstract: A method for producing a metallic strip is disclosed. A metallic melt containing above about 20% by weight of iron is formed into a strip so that fine iron particles are distributed throughout. The strip may be rolled to elongate the iron particles.
Abstract: A magneto-optical device for varying the state of polarization of a reflected or transmitted light beam having a wavelength which lies in particular in the range between 0.6 and 0.9 microns. The device has a magneto-optically active layer formed from a platinum-manganese-antimony alloy, at least 80 atomic percent of which has the composition Pt.sub.1 Mn.sub.1 Sb.sub.1 and has a C1.sub.b crystal structure.
Type:
Grant
Filed:
January 17, 1985
Date of Patent:
March 17, 1987
Assignee:
U.S. Philips Corporation
Inventors:
Pieter G. van Engen, Kurt H. J. Buschow, Ronald Jongebreur