Abstract: A sintered magnet and a rotating machine equipped therewith are disclosed, which include: crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or an oxyfluoride compound, containing at least one element selected from the group consisting of an alkali metal element, an alkaline earth metal element, and a rare earth element, the fluoride compound or the oxyfluoride compound being formed inside some of the crystal grains or in a part of a grain boundary part. The oxyfluoride compound or the fluoride compound contains carbon, and a grain boundary width of the ferromagnetic material is smaller than a grain boundary width of the ferromagnetic material in which the fluoride compound or the oxyfluoride compound is formed.

Abstract: A powder compressed magnetic core, which is produced by compressing iron powder or alloy powder of which the main component is iron. A fluoride compound layer of a fluoride of a rare earth element or a fluoride of an alkaline earth metal is formed on the surface of the powder, and an under layer is formed between the fluoride layer and the iron powder or the alloy powder.

Abstract: A rare earth element magnet comprising molded magnetic powder containing at least one rare earth element, wherein a Fe rich phase covering a part or entire of the surface of particles of the magnetic powder and having a Fe atomic percentage larger than that of the magnetic powder, and an inorganic binder bonding the particles covered with the Fe rich phase.

Abstract: A manufacturing method of a magnetic core includes a first step of applying a treatment liquid for forming an insulating film to iron powder; a second step of heat-treating the iron powder to which the treatment liquid has been applied, at a temperature higher than 350 degrees; a third step of compacting the heat-treated iron powder to form a magnetic core; and a forth step of heat-treating the magnetic core at a temperature ranging from 600 degrees to 800 degrees.

Abstract: A magnet which includes ferromagnetic powder to be mainly a mother phase containing iron or cobalt. The ferromagnetic powder is provided with a high-resistance layer which has a resistance higher than or equal to ten times as high as a resistance of the mother phase and a Vickers hardness lower than a Vickers hardness of the mother phase. The high-resistance layer is being formed partially or entirely on the surface of the ferromagnetic powder.

Abstract: A magnet comprising magnetic powder containing at least one rare earth metal element, and an oxide binder for binding the magnetic powder, wherein an inter-face distance of the binder determined by diffraction analysis is 0.25 to 2.94 nm. The disclosure also discloses a method of manufacturing a magnet comprising; compacting magnetic powder containing at least one rare earth element under pressure in a mold; impregnating the compacted magnetic powder molding with a precursor solution of an oxide material; and heat-treating the compacted magnetic molding impregnated with the precursor thereby to impart an inter-face distance determined by diffraction analysis to the binder in the compacted molding. The distance is 0.25 to 2.94 nm.

Abstract: A compacted magnetic core with a high resistance, which comprises compacted magnetic powder of an iron powder or an alloy powder containing iron as a main ingredient and a layer of a rare earth metal fluoride or an alkaline earth metal fluoride on the surface of the powder, wherein the rare earth metal fluoride or the alkaline earth metal fluoride contains fluorine-depleted crystal lattice at a rate of 10% or less.

Abstract: Eddy current generated around a magnetic circuit in an MRI apparatus is one of the causes of deviation from an ideal magnetic field gradient waveform and causes image distortion, loss of strength, ghost generation, loss of signal, and spectral distortion. An object of the present invention is to suppress the generation of the eddy current. In an MRI apparatus, a ferromagnetic material formed from powder is used in a part of a magnetic circuit: the powder mainly comprising a mother phase containing iron or cobalt and showing ferromagnetism; and a high-resistance layer having a resistance not less than ten times as high as the mother phase and a Vickers hardness lower than that of the mother phase being formed in layers along parts of the surface of the powder on parts or the entire of the surface.

Abstract: A magnet comprising grains of a ferromagnetic material whose main component is iron and a fluorine compound layer or an oxy-fluorine compound layer of fluoride compound particles of alkali metals, alkaline earth metals and rare earth elements, present on the surface of the ferromagnetic material grains, wherein an amount of iron atoms in the fluorine compound particles is 1 to 50 atomic %.

Abstract: A magnetoresistive head comprises a free magnetic layer that has first and second free magnetic films sandwiching a non-magnetic intermediate film therebetween, the respective magnetizing directions of the first and the second free magnetic films are antiparallel. The length of the free magnetic layer in the direction of the track width is 200 nm or less, and a difference between a product of saturation magnetic flux density and a film thickness of the first free magnetic film, and that of the second free magnetic film is within a range from 1 to 3 nmT. By this structure, the variation of output and the variation of asymmetry is greatly decreased at a track width of 200 nm or less.

Abstract: A magnetic powder according to the present invention comprises powder made of the iron element as a main component, and an insulator covering the surface of the powder. The powder has a spherical shape or a smoothed surface. The insulator comprises rare earth fluorides, alkaline metal fluorides, or alkaline earth metal fluorides. A soft magnetic composite formed by using this magnetic powder can suppress its eddy current loss in a wide frequency band and can also suppress its hysteresis loss due to compressed residual distortion in soft magnetic powder.

Abstract: A magnetoresistive head comprises a free magnetic layer that has first and second free magnetic films sandwiching a non-magnetic intermediate film therebetween, the respective magnetizing directions of the first and the second free magnetic films are antiparallel. The length of the free magnetic layer in the direction of the track width is 200 nm or less, and a difference between a product of saturation magnetic flux density and a film thickness of the first free magnetic film, and that of the second free magnetic film is within a range from 1 to 3 nmT. By this structure, the variation of output and the variation of asymmetry is greatly decreased at a track width of 200 nm or less.

Abstract: The object of the present invention is to both reduce costs and improve magnetic characteristics of rare-earth bond magnets in which magnetic material is bound with a binding agent. In order to achieve this object, magnetic characteristics of a magnet are improved by performing cold forming on rare-earth magnetic powder by itself with no resin added. Then, in order to provide strength for the magnet, a low-viscosity SiO2 precursor is infiltrated and thermoset in the magnet shaped body. As a result, it is possible to obtain a rare-earth bond magnet in which magnetic characteristics are improved and costs are reduced.

Abstract: Eddy current generated around a magnetic circuit in an MRI apparatus is one of the causes of deviation from an ideal magnetic field gradient waveform and causes image distortion, loss of strength, ghost generation, loss of signal, and spectral distortion. An object of the present invention is to suppress the generation of the eddy current. In an MRI apparatus, a ferromagnetic material formed from powder is used in a part of a magnetic circuit: the powder mainly comprising a mother phase containing iron or cobalt and showing ferromagnetism; and a high-resistance layer having a resistance not less than ten times as high as the mother phase and a Vickers hardness lower than that of the mother phase being formed in layers along parts of the surface of the powder on parts or the entire of the surface.

Abstract: A lamellar high resistance layer having resistivity ten times or higher than that of a mother phase containing iron or cobalt is formed and an oxygen content is controlled to 10 to 10000 ppm so that the reliability and residual magnetic flux density are increased.

Abstract: A magnetoresistive head comprises a free magnetic layer that has first and second free magnetic films sandwiching a non-magnetic intermediate film therebetween, the respective magnetizing directions of the first and the second free magnetic films are antiparallel. The length of the free magnetic layer in the direction of the track width is 200 nm or less, and a difference between a product of saturation magnetic flux density and a film thickness of the first free magnetic film, and that of the second free magnetic film is within a range from 1 to 3 nmT. By this structure, the variation of output and the variation of asymmetry is greatly decreased at a track width of 200 nm or less.

Abstract: A magnetoresistive head comprises a free magnetic layer that has first and second free magnetic films sandwiching a non-magnetic intermediate film therebetween, the respective magnetizing directions of the first and the second free magnetic films are antiparallel. The length of the free magnetic layer in the direction of the track width is 200 nm or less, and a difference between a product of saturation magnetic flux density and a film thickness of the first free magnetic film, and that of the second free magnetic film is within a range from 1 to 3 nmT. By this structure, the variation of output and the variation of asymmetry is greatly decreased at a track width of 200 nm or less.

Abstract: A magnetoresistive head comprises a free magnetic layer that has first and second free magnetic films sandwiching a non-magnetic intermediate film therebetween, the respective magnetizing directions of the first and the second free magnetic films are antiparallel. The length of the free magnetic layer in the direction of the track width is 200 nm or less, and a difference between a product of saturation magnetic flux density and a film thickness of the first free magnetic film, and that of the second free magnetic film is within a range from 1 to 3 nmT. By this structure, the variation of output and the variation of asymmetry is greatly decreased at a track width of 200 nm or less.

Abstract: An oxide layer and an antiparallel coupling layer are inserted into a ferromagnetic pinned layer to be subjected to heat treatment with appropriate ferromagnetic film thickness and magnetization field to form a spin-valve film, which is controlled in amount of magnetization and is high in magnetoresistance.

Abstract: An oxide layer or a mixture layer of an oxide and a magnetic body is formed on an interface between an antiferromagnetic coupling layer and a ferromagnetic layer in a synthetic ferrimagnetic structure. In this case, antiferromagnetic coupling between the ferromagnetic layer and another ferromagnetic layer does not deteriorate considerably. This structure is used for a magnetization fixed layer or a free ferromagnetic layer in a spin valve, whereby a high-output magnetic head and a high-output magnetic disc device can be produced.