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Showing papers on "Magneto published in 2002"


Journal ArticleDOI
TL;DR: In this article, a new magnetic waveguide is described, the operation of which is based on inductive coupling between resonant elements, and the general form of the dispersion equation is shown.
Abstract: A new magnetic waveguide is described, the operation of which is based on inductive coupling between resonant elements. The general form of the dispersion equation is shown. For a particular embodiment of the waveguide, consisting of 26 elements, the relative values of the currents are plotted and the travel of power from the first to the last element is shown by the streamlines of the Poynting vector. Application, as a magnetic guide for magnetic resonance imaging (MRI) is proposed.

231 citations


Journal ArticleDOI
TL;DR: In this article, an oscillatory test method was proposed to determine the viscoelastic properties of a magneto-rheological fluid as a function of the preset magnetic field strength.
Abstract: Abstract The viscoelastic properties of a magneto-rheological fluid can be variably controlled using a magnetic field. A new measuring method is introduced which is based on oscillatory tests. In contrast to flow curves from experiments at steady shear rate, the new method allows an exact determination of a magneto-rheological fluid’s viscoelastic properties as a function of the preset magnetic field strength. The “Magneto Sweep” is an oscillatory test method, each with constant amplitude and constant frequency while logarithmically increasing the magnetic field strength (Magneto Sweep). For typical magneto-rheological fluids (MRF) three characteristic regions and two significant transition points can be determined. These transitions mark the corresponding change in material behavior resulting from an increasing magnetic field strength.

58 citations


Patent
30 Aug 2002
TL;DR: In this paper, the first and second magneto-resistive effect elements are laminated through a nonmagnetic intermediate gap layer in such a manner that their magnetic flux sensing films are located close to each other.
Abstract: First and second magneto-resistive effect elements ( 1 ) and ( 2 ) of a current perpendicular to plane type having magnetic flux sensing films are laminated through a nonmagnetic intermediate gap layer ( 3 ) in such a manner that their magnetic flux sensing films are located close to each other. Then, magneto-resistive change characteristics are caused to become opposite to each other so that a differential output between the output of the first and second magneto-resistive effect elements may be generated as a magnetic sensor output or a differential output between the output of the first and second magneto-resistive effect elements may be generated as a differential output in an external circuit configuration. In this manner, a resolution can be improved by a configuration in which a gap length, which decides a resolution, may not be restricted by a thickness of a magneto-resistive effect element. Therefore, restrictions imposed on the resolution in the MR magnetic sensor can be improved.

36 citations


Patent
15 Mar 2002
TL;DR: In this paper, a magnetic memory device with first and second soft reference layers, first barrier layers, and a sense layer bound between the barrier layers and the soft reference layer is described.
Abstract: A magnetic memory device is disclosed that includes first and second soft reference layers, first and second barrier layers, and a sense layer, bound between the first and second barrier layers, which are further bound by the first and second soft reference layers.

26 citations




Patent
29 Jan 2002
TL;DR: In this paper, a bearing sensor has a thin plane coil for applying a biasing magnetic field and at least one magneto resistive element pair crossing opposed conductor sides of the plane coil.
Abstract: To provide a bearing sensor having a thin plane coil for applying a biasing magnetic field and at least one magneto resistive element pair (a first magneto resistive thin plate and a second magneto resistive thin plate) crossing opposed conductor sides of the coil. The plane coil has at least one pair of opposed conductor sides (a first side and a second side). The first magneto resistive thin plate and the first side cross one another at an angle more than 30 degrees and less than 90 degrees. The second magneto resistive thin plate and the second side cross one another at an angle more than 30 degrees and less than 90 degrees. While biasing magnetic fields in opposite directions are applied to the magneto resistive thin plates, respectively, intermediate potentials of the magneto resistive element pair are measured to determine bearings based on the difference between the intermediate potentials.

14 citations


Journal Article
01 Jan 2002-Scopus
TL;DR: In this article, the existence of a reproductive weak solution for the equations of motion of magneto-micropolar fluids in exterior domains in R^3 was established, which is called periodic weak solution.
Abstract: We establish the existence of a reproductive weak solution, a so-called periodic weak solution, for the equations of motion of magneto-micropolar fluids in exterior domains in R^3.

13 citations



Journal ArticleDOI
TL;DR: In this article, a kind of elastic magnetic fluid support representing the magnetic fluid drop with permanent magnet inside is investigated experimentally and numerically, and the dependencies between the magneto static force in support and the geometrical parameters and properties of the magnet and the fluid are established.

11 citations


Patent
04 Mar 2002
TL;DR: In this paper, the authors proposed a manufacturing method for a tunneling magneto resistive effect device, which consists of a first process for forming a conducting layer, and a second process for oxidizing the conducting layer.
Abstract: PROBLEM TO BE SOLVED: To provide a tunneling magneto resistive effect device which exhibits greater magneto resistivity with reduced degrading of a TMR ratio due to bias voltage, and which has higher heat resistance. SOLUTION: In a manufacturing method for a tunneling magneto resistive effect device, a process for forming a tunneling insulating layer of the tunneling magneto resistive effect device comprises a first process for forming a conducting layer being a tunneling insulating layer precursor, and a second process for oxidizing the conducting layer. In the first process for forming the conducting layer the rate of film formation is 0.4 Å/sec or less. COPYRIGHT: (C)2003,JPO


Patent
Takeshi Kajiyama1
19 Apr 2002
TL;DR: In this article, the first magnetic layer and the first non-magnetic layer are formed in a direction perpendicular to the semiconductor substrate, and the magnetic layer is separated from the substrate by a magneto resistive element.
Abstract: A semiconductor memory device includes a semiconductor substrate, and a first magneto resistive element separated from the semiconductor substrate, and including a first magnetic layer and a first nonmagnetic layer. The first magnetic layer and the first nonmagnetic layer are formed in a direction perpendicular to the semiconductor substrate.




Proceedings ArticleDOI
04 Jun 2002
TL;DR: In this article, a radial flux generator with surface mounted magnets operating at 200 kW, 3600 RPM, 720 Hz is described, which is intended for use with a rectifier on the output which feeds a DC link and inverter.
Abstract: In recent years, permanent magnet materials together with power electronic devices have improved both in terms of performance and commercialisation. Machine hybrids including permanent magnet materials and power electronics are already widely used. in industry and ratings are expected to increase. The design of a radial flux generator with surface mounted magnets operating at 200 kW, 3600 RPM, 720 Hz is included in this paper. The machine design described is intended for use with a rectifier on the output which feeds a DC link and inverter as part of a variable speed integrated generating set (VSIG). The main aim of the paper is to study, for a given mass of permanent magnet material, the merits of using a 120 pole arc compared with a 180 degree pole arc. Electrical parameters such as voltage waveform, inductance, voltage regulation and power output are compared. Eddy current loss in the magnet and rotor together with eddy current loss and hysteresis in the stator are examined. The calculation methods are detailed and an FEA rotating machine solver used. A machine has been built and tested and electrical measurements are compared to calculations.

Patent
Takeshi Kajiyama1
19 Apr 2002
TL;DR: In this paper, the first magnetic layer and the first non-magnetic layer are formed in a direction perpendicular to the semiconductor substrate, and the magnetic layer is separated from the substrate by a magneto resistive element.
Abstract: A semiconductor memory device includes a semiconductor substrate, and a first magneto resistive element separated from the semiconductor substrate, and including a first magnetic layer and a first nonmagnetic layer. The first magnetic layer and the first nonmagnetic layer are formed in a direction perpendicular to the semiconductor substrate.


Patent
12 Apr 2002
TL;DR: In this article, the authors characterize a magnetic sensitive layer with a magnetization in plane, forming a current perpendicular to plane type magneto resistive effect film 4 which perpendicularly runs the sense current to a film plane and carrying out patterning into a component configuration.
Abstract: PROBLEM TO BE SOLVED: To make it possible to prevent the fall of the yield and generation of the Barkhausen noise as much as possible. SOLUTION: This method is characterize in comprising a step of including a magnetic sensitive layer with a magnetization in plane, forming a current perpendicular to plane type magneto resistive effect film 4 which perpendicularly runs the sense current to a film plane and carrying out patterning into a component configuration, and a step of forming a magnetic yoke 12 which covers the magneto resistive effect film 4 carried out patterning into the component configuration.

Patent
17 Sep 2002
TL;DR: In this paper, a spin valve magneto resistive effect reproducing head is provided with a lead overlay structure to exhibit good magnetic reproducing characteristics, and its manufacturing method is described. But, it is not shown how to obtain a clear effective reading width.
Abstract: PROBLEM TO BE SOLVED: To provide a spin valve magneto resistive effect reproducing head provided with a lead overlay structure to exhibit good magnetic reproducing characteristics, and its manufacturing method. SOLUTION: This head is provided with a longitudinal bias layer formed to be adjacently joined to the first end surface of a magneto resistive effect film, and a conductive lead overlay layer formed to cover the longitudinal bias layer and to be electrically joined to the second end surface of the magneto resistive effect film. Thus, a good current path is formed, and a clear effective reading width is defined. Especially, since the second end surface is formed by using ion-beam etching, damage to a ferromagnetic free layer is prevented. COPYRIGHT: (C)2003,JPO


Patent
18 Sep 2002
TL;DR: In this article, a bearing sensor has a thin plane coil for applying a biasing magnetic field and at least one magneto resistive element pair crossing opposed conductor sides of the plane coil.
Abstract: To provide a bearing sensor having a thin plane coil for applying a biasing magnetic field and at least one magneto resistive element pair (a first magneto resistive thin plate and a second magneto resistive thin plate) crossing opposed conductor sides of the coil The plane coil has at least one pair of opposed conductor sides (a first side and a second side) The first magneto resistive thin plate and the first side cross one another at an angle more than 30 degrees and less than 90 degrees The second magneto resistive thin plate and the second side cross one another at an angle more than 30 degrees and less than 90 degrees While biasing magnetic fields in opposite directions are applied to the magneto resistive thin plates, respectively, intermediate potentials of the magneto resistive element pair are measured to determine bearings based on the difference between the intermediate potentials

Patent
15 Mar 2002
TL;DR: In this article, a magnetoresistance effect type magnetic head is provided with a magneto-resistance effect film (a FeNi layer) showing a magnetic resistance effect by which the change of an external magnetic field is sensed as the change in electric resistance to a sense current and the Co based magnetic domain controlling films 2a and 2b positioned in the both ends of the magneto resistance effect film 6 and consisting of base layers 8 and Co-based magnet films 9 which are repetitively laminated and apply magnetization in an intra-surface direction (direction of an arrow A
Abstract: PROBLEM TO BE SOLVED: To apply a desired magnetic field to a MR element by means of a pair of Co based magnetic domain controlling films. SOLUTION: A magnetoresistance effect type magnetic head is provided with a magneto-resistance effect film (a FeNi layer) 6 showing a magneto- resistance effect by which the change of an external magnetic field is sensed as the change of electric resistance to a sense current and the Co based magnetic domain controlling films 2a and 2b positioned in the both ends of the magneto resistance effect film 6 and consisting of base layers 8 and Co based magnet films 9 which are repetitively laminated and the Co based magnetic domain controlling films 2a and 2b apply magnetization in an intra-surface direction (direction of an arrow A) to the magneto-resistance effect film 6. The MR head is capable of preventing Barkhausen noise and obtaining satisfactory reproducing output without disturbing a reproducing waveform.


Patent
13 Feb 2002
TL;DR: In this article, a magnetoelectric igniter for power fuel of apparatuses used under oil well and gas well was described, where a magnetic ring winded with two coils is installed on the original electric igniter.
Abstract: The utility model discloses a magnetoelectric igniter for power fuel of apparatuses used under oil well and gas well. Essential structure of the igniter is that a magnetic ring winded with two coils is installed on the original electric igniter. Primary coil group of the magnetic ring and a housing form an input circuit. Secondary coil and an electrode cap form an output circuit. Only in cooperation with a magnetoelectric explosive initiator, the utility model can realize ignition. Power of common working frequency, static, jet frequency and stray current in the downhole construction environment can not make the igniter output flame, thereby promising extremely high safety and effectively prevent the economic loss caused by accidental ignition.

Patent
20 Jun 2002
TL;DR: In this paper, a device having a magneto-resistive element, a first conductor proximate to the magneto resistive element and a second conductor proximally to it is considered, and the second electrical pulse is delayed relative to the first electrical pulse.
Abstract: A device having a magneto-resistive element, a first conductor proximate to the magneto-resistive element, and a second conductor proximate to the magneto-resistive element. The magneto-resistive element is exposed to a magnetic field generated by a first electrical pulse carried by the first conductor. The magneto-resistive element is also exposed to a magnetic field generated by a second electrical pulse carried by the second conductor. The second electrical pulse is delayed relative to the first electrical pulse.

01 Jan 2002
TL;DR: In this paper, the experimental observation of three magneto-optical phenomena: magnetoelectric Jones birefringence, magneto chiral dichroism, and enantioselective magnetochiral photochemistry was reported.
Abstract: We report the experimental observation of three new magneto-optical phenomena: (i) magneto-electric Jones birefringence, (ii) magneto-chiral dichroism and (iii) enantioselective magneto-chiral photochemistry.


Patent
07 Jun 2002
TL;DR: In this article, the authors proposed a magnetic field stator of magneto electric motor capable of reducing noise with insensitive to accuracy of inner diameter of a field magnetic stator, which consists of a cylindrical-shaped yoke 1, a plurality of fan-shaped permanent magnets 2, auxiliary magnetic poles 3 and a few stays 4 with roughly U-shaped cross sections fixed to the yoke.
Abstract: PROBLEM TO BE SOLVED: To provide a magnetic field stator of magneto electric motor capable of reducing noise with insensitive to accuracy of inner diameter of a field magnetic stator. SOLUTION: A field magnetic field stator comprises a cylindrical-shaped yoke 1, a plurality of fan-shaped permanent magnets 2, auxiliary magnetic poles 3 and a plurality of stays 4 with roughly U-shaped cross sections fixed to the yoke 1, The permanent magnets 2 and the magnet poles 3 are arranged between adjacent stays 4 to fix the magnets 2 and the poles 3 to an inner circumferential surface of the yoke 1 in the radial direction by using spring- reaction force while deforming elastically the stays 4. Moreover, projections 41 provided at both ends of the stays 4 are deformed with bending to hold the magnets 2 and the poles 3 in the thrust direction.