Magnetic circuit and method of applying magnetic field
AssigneeShin-Etsu Chemical Co., Ltd.
InventorKen Ohashi
Life of this patent
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Abstract
In a magnetic circuit for providing magnetic anisotropy in the in-plane radial direction of a soft magnetic under layer, magnets for perpendicular magnetization are respectively provide on the north and south poles of a magnet for horizontal magnetization. When magnetic circuits configured thus are stacked in a plurality of stages, a magnetic field (air-gap magnetic field) formed in a gap between the magnetic circuits is superimposed by magnetic fields from the magnets for perpendicular magnetization as well as a magnetic field from the magnet for horizontal magnetization (in-plane magnetization). The pole faces of the magnets for perpendicular magnetization are disposed closer to the gap between the magnetic circuits, so that a stronger magnetic field can be formed in the gap.
Claims12
A magnetic circuit for storing a sample in a gap formed between a plurality of magnetic field application parts opposed to each other in parallel and applying a magnetic field to the sample,
- wherein each of the magnetic field application parts includes a plurality of permanent magnet segments, the permanent magnet segments including:
- a first permanent magnet horizontally magnetized in parallel with an opposed surface of the magnet field application part,
- a second permanent magnet magnetized perpendicularly to the opposed surface of the magnetic field application part, the second permanent magnet being provided on a north pole of the first permanent magnet, and
- a third permanent magnet perpendicularly magnetized in an opposite direction from the second magnet, the third permanent magnet being provided on a south pole of the first permanent magnet,
- wherein the magnetic field application parts are configured like a notched ring around a virtual axis with a combination of the plurality of first to third permanent magnets, the first permanent magnet is disposed such that the first permanent magnet is magnetized perpendicular to the virtual axis, and wherein the notched portion of the ring is formed by removing a part of the combination of first to third permanent magnets.
A magnetic circuit for applying a magnetic field to a sample positioned in a gap of the magnetic circuit, comprising:
- a plurality of magnetic field application parts including a first magnetic field application part and a second magnetic field application part, wherein the first magnetic field part is positioned parallel to and spaced apart from the second magnetic field application part in a vertical direction to form the gap therebetween, wherein the first and the second magnetic field application parts each include a plurality of permanent magnet segments arranged around a virtual axis, extending in the vertical direction, to form an incomplete ring around the virtual axis, wherein the permanent magnet segments of the first and the second magnetic field application parts include:
- a first permanent magnet magnetized in a horizontally direction;
- a second permanent magnet magnetized in a vertical direction, the second permanent magnet being positioned on a north pole of the first permanent magnet;
- and
- a third permanent magnet magnetized in a direction opposite to the direction of magnetization of the second permanent magnet, the third permanent magnet being positioned on a south pole of the first permanent magnet, wherein the plurality of permanent magnet segments are arranged around the virtual axis such that the magnetization direction of each first permanent magnet is oriented perpendicular to the virtual axis.
Dependencies are inferred from the claim text.