Abstract: A magnetic recording medium was a high normalized coercive force and superior thermal stability. The magnetic recording medium comprises a non-magnetic base material, and a ferromagnetic metal layer of cobalt based alloy formed on top of this base material with a metal underlayer disposed therebetween, and displays a coercive force Hc of at least 2000 (Oe) and an anisotropic magnetic field Hkgrain of at least 10,000 (Oe). Furthermore, magnetic recording media in which the aforementioned metal underlayer and/or the ferromagnetic metal layer are fabricated in a film fabrication chamber with an ultimate vacuum at the 10?9 Torr level are preferred. A magnetic recording medium according to the present invention can be ideally applied to hard disks, floppy disks, and magnetic tapes and the like.

Abstract: A magnetic thin film with a saturation magnetic flux density of 2 T or more and a coercive force of 2 Oe or less for a magnetic pole material of a recording head. The magnetic thin film consists of an iron carbide film that includes a martensite (??) phase as the principal phase and at least carbon and iron as constituent elements. The iron carbide film preferably consists of a single ?? phase. The iron carbide film has a body-centered tetragonal structure and a c-axis constitutes an axis of hard magnetization and, a c-plane constitutes a plane of easy magnetization. The axis of hard magnetization constitutes a direction which is generally perpendicular to the film surface, and the plane of easy magnetization constitutes a direction which is generally parallel to the film surface.

Abstract: A vertical magnetic recording medium enabling information recording/reproduction with high-recording density and having a soft magnetic backing layer that enables low-noise recording, can be thin, and is excellent in corrosion resistance and its manufacturing method are disclosed. The vertical magnetic recording medium (10) having a soft magnetic backing layer (12) and a vertical recording layer (12) as to serve as a main recording layer and having an easy-magnetization axis mainly oriented vertically to the film surface is characterized in that the soft magnetic backing layer (12) characterized by being made of a soft magnetic material having a composition of FeTaN.

Abstract: A magnetic recording medium having a high normalized coercive force of a ferromagnetic metal layer and excellent S/N ration and adaptable to high density recording. The magnetic recording medium comprises a substrate body and a Co-based ferromagnetic metal layer formed thereon via a metallic underlying layer. The oxygen concentrations in the metallic underlying layer and in the ferromagnetic metal layer are not larger that 100 wt ppm. Magnetic in version is used for the recording. The value of 4ΠMs/Hkgrain is the saturation magnetization of the ferromagnetic metal layer and Hkgrain is the anisotropic magnetic field of the individual crystalline particles constituting the ferromagnetic metal layer is 1 or less.

Abstract: A magnetic recording medium capable of suppressing the effects of thermal agitation and simultaneously reducing the average grain diameter and the standard deviation of magnetic crystal grains constituting a ferromagnetic metal film, without changing the film thickness of a metal under-layer or the film thickness of a ferromagnetic metal layer forming a recording layer, as well as a production method thereof, and a magnetic recording device. The magnetic recording medium includes a ferromagnetic metal layer of a cobalt based alloy formed on a base material with a metal underlayer having chromium as a major constituent disposed there between, wherein a seed layer having at least tungsten is provided between the base material and the metal under-layer, and the seed layer is an islands type film.

Abstract: The magnetic alloy includes cobalt (Co), chromium (Cr), and germanium (Ge), the composition of the magnetic alloy being represented by the general formula: CoxCryGez where x, y and z, which represent the composition ratio in terms of atomic %, satisfy the relationships: 78≦x≦87, 2.5≦y≦14.5, 3.5≦z≦15 and x+y+z=100. The magnetic alloy may have a composition represented by the formulas: CoCrGeT (T represents one or more elements of Ta, Si, Nb, B, Ni and Pt) or a composition represented by the formula: CoCrGeT′ (T′ represents one or more elements of Ta, B, and Pt).

Abstract: A magnetic recording medium having a high coercive force of a ferromagnetic metal layer, a high anisotropic magnetic field and/or normalized coercive force, and adaptable to high density recording. The magnetic recording medium includes a substrate body and a ferromagnetic metal layer containing at least Co and Cr formed thereon via a metallic underlying layer of Cr. Magnetic inversion is utilized for the recording. A first region which penetrates through the ferromagnetic metal layer and in which Cr is segregated are formed among the crystal grains constituting the ferromagnetic metal layer. The Cr concentration in the intermediate portions of the first region in the direction of thickness of the ferromagnetic metal layer is smaller than that of the portions near the surface and near the metallic underlying layer.

Abstract: A vertical magnetic recording medium and a method for evaluating the same by which the thickness of the micro-crystalline texture part occupying the ferromagnetic layer in the recording layer of the medium can be grasped quantitatively along with the distribution thereof in the thickness direction and the crystal magnetic anisotropy constant Kugrain of magnetic crystal grains in a columnar texture part can be determined simultaneously.

Abstract: A method of manufacturing a magnetoresistance element which can reproduce magnetic signals with higher sensitivity. The manufacturing method includes the steps of providing a vacuum below 10−9 Torr in a film forming chamber for forming a nonmagnetic layer and ferromagnetic layer; performing plasma-etching of the surface of a substrate body by using a mixture of a gas (a) containing at least oxygen or water introduced into the chamber and an Ar gas (b) introduced into the chamber in a vacuum, state controlled to higher than 10−9 Torr; and forming the nonmagnetic and ferromagnetic layers on the etched substrate body by sputtering a prescribed target by using the mixture of the gases (a) and (b).

Abstract: A magnetic recording medium having a high normalized coercive force of a ferromagnetic metal layer and excellent S/N ration and adaptable to high density recording. The magnetic recording medium comprises a substrate body and a Co-based ferromagnetic metal layer formed thereon via a metallic underlying layer. The oxygen concentrations in the metallic underlying layer and in the ferromagnetic metal layer are not larger that 100 wt ppm. Magnetic in version is used for the recording. The value of 4ΠMs/Hkgrain is the saturation magnetization of the ferromagnetic metal layer and Hkgrain is the anisotropic magnetic field of the individual crystalline particles constituting the ferromagnetic metal layer is 1 or less.

Abstract: A magnetic recording medium with a favorable S/N ratio, for which a high coercive force is possible, as well as a method of producing such a medium, and a magnetic recording device which utilizes such a medium. The magnetic recording medium includes a non-magnetic substrate, and a nucleation layer, a metal underlayer, and a ferromagnetic metal layer for recording magnetic information formed either directly or indirectly on top of the non-magnetic substrate, wherein the nucleation layer includes either an alloy incorporating at least Nb, or an alloy incorporating at least one element selected from the group consisting of V, Mo and W. Moreover, the nucleation layer should preferably also include at least one element selected from the group consisting of Ni, Co, Fe and Cu. The magnetic recording medium according to the present invention can be ideally applied to hard disks, floppy disks, and magnetic tapes and the like.

Abstract: The present invention provides a magnetic recording medium with a high normalized coercive force and superior thermal stability, as well as a method of producing such a magnetic recording medium and a magnetic recording device incorporating such a magnetic recording medium. A magnetic recording medium according to the present invention comprises a non-magnetic base material, and a ferromagnetic metal layer of cobalt based alloy formed on top of this base material with a metal underlayer disposed therebetween, and displays a coercive force Hc of at least 2000 (Oe) and an anisotropic magnetic field Hkgrain of at least 10,000 (Oe). Furthermore, magnetic recording media in which the aforementioned metal underlayer and/or the ferromagnetic metal layer are fabricated in a film fabrication chamber with an ultimate vacuum at the 10−9 Torr level are preferred.

Abstract: A fluid control valve, which can control a fluid having a pressure in the order of 10 kg/cm2, has a response time in the order of several milliseconds can be made small in size, and a fluid supply/exhaust system that provides less gas counter flow in the event of a plurality of valves being used. A fluid control valve of the invention controls a fluid moving in a valve body by closing and opening a portion between a valve seat and a valve holder by use of a drive unit. The drive unit has a rod-shaped shaft for application of pressure through the valve seat and the valve holder, and a member “a” fixed around the rod-shaped shaft. The member “a” is made from a magnetic material, and has a space between it and the shaft. A coil provided in parallel to the shaft, moves the shaft via the member “a” up and down by electromagnetic induction, and makes use of a spring force to close and open a portion between the valve seat and the valve holder.

Abstract: A fluid control valve, which can control a fluid having a pressure in the order of 10 kg/cm2, has a response time in the order of several milliseconds can be made small in size, and a fluid supply/exhaust system that provides less gas counter flow in the event of a plurality of valves being used. A fluid control valve of the invention controls a fluid moving in a valve body by closing and opening a portion between a valve seat and a valve holder by use of a drive unit. The drive unit has a rod-shaped shaft for application of pressure through the valve seat and the valve holder, and a member “a” fixed around the rod-shaped shaft. The member “a” is made from a magnetic material, and has a space between it and the shaft. A coil provided in parallel to the shaft, moves the shaft via the member “a” up and down by electromagnetic induction, and makes use of a spring force to close and open a portion between the valve seat and the valve holder.

Abstract: This invention aims at providing magnetooptic thin film having a high Kerr rotation angle (&thgr;k) in a short wave band, etc., magnetooptic recording medium and a method of providing them. The magnetooptic thin film has an alloy composition is MnxSbyPtz, 45≦x≦56, 40≦y≦48, 2≦z≦15 and x+y+z=100 (where x, y and z are proportions in atomic %), and a ratio &agr;/&bgr; of a diffraction intensity from a (220)-plane of a C1b type crystalline structure of the magnetooptic thin film in X-ray diffraction intensity &bgr; from a (110)-plane of a B81 type crystalline structure in from 0.05 to 1.0. The film thickness of the magnetooptic thin film is from 10 nm to 300 nm. The production method of the magnetooptic thin film is characterized in that the substrate, on which the magnetooptic thin film is to be formed, is heat-treated on a vacuum at most 5×10−6 Torr at a temperature not lower than 100° C. for at least 30 minutes before the thin film is formed.

Abstract: A mass-producible magnetic recording medium having a ferromagnetic metal layer comprising CoNiCr or CoCrPt alloy, which has a high S/N ratio of electromagnetic conversion and a stable coercive force.The magnetic recording medium, using magnetic inversion, has a ferromagnetic metal layer comprising CoNiCr or CoCrPt formed on a surface of a substrate body with a metallic base layer therebetween. The ferromagnetic metal layer has an oxygen concentration of not more than 100 wt ppm and contains crystal grains with an amorphous grain boundary.In the manufacturing process according to the present invention, the metallic base layer and/pr the ferromagnetic layer is formed on the substrate body at 60 .degree. C.-150.degree. C.

Abstract: A magnetic recording medium comprising a smooth recording layer constituted of magnetic particles having a small size, which has a high coercive force. The magnetic recording medium comprises a substrate body, a Cr undercoat with an oxygen content of 100 wt ppm or less, and ferromagnetic metal made of CoCrTa having an oxygen content of 100 wt ppm or less, and which utilizes magnetic inversion. The ferromagnetic metal layer comprises 14 to 23 atm % chromium(Cr), 2 to 8 atom % tantalum(Ta) and the balance of cobalt(Co).

Abstract: A magnetoresistance element for reproducing magnetic signals with higher sensitivity and its manufacturing method. The magnetoresistance element has a structure including alternate layers of ferromagnetic material and nonmagnetic material on a substrate, and the oxygen concentration in the structure is less than 100 wt. ppm. Alternatively, the magnetoresistance element comprises a substrate, a nonmagnetic layer on the substrate, a ferromagnetic layer on the nonmagnetic layer on the substrate, a ferromagnetic layer on the nonmagnetic layer, and an antiferromagnetic layer on the ferromagnetic layer, and the oxygen concentration in the part where the ferromagnetic material layers are laminated with the nonmagnetic material layers in between is less than 100 wt. ppm.

Abstract: A magnetic recording medium having a large coercive force independent of the material of the substrate body by employing an .alpha.-rich layer and a .beta.-rich layer. The magnetic recording medium, using magnetic inversion, comprises a substrate body and a ferromagnetic Co-alloy layer on the surface of the substrate body. Between the substrate body and the magnetic layer may be interposed a Cr-containing metallic base layer. The base layer and/or the ferromagnetic alloy layer has an oxygen concentration of not more than 100 wt ppm. An .alpha.-rich layer of nickel, phosphorus, and the oxides thereof, and a .beta.-rich layer containing an ester group are provided between the substrate body and the base layer or the ferromagnetic alloy layer. In the manufacturing process according to the present invention, the .alpha.-rich layer, a .beta.-rich layer, metal base layer, and ferromagnetic metallic layer are formed at pressure below the order of 10.sup.-9 Torr.

Abstract: An inexpensive high-density recording medium which is increased in coercive force without using expensive ferromagnetic metallic layer. In a magnetic recording medium on the base body of which a ferromagnetic metallic layer is formed on a base body with a metallic underlying layer in between and which utilizes reversal of magnetization, the oxygen concentration in the ferromagnetic metallic layer is 100 wt. ppm or less, and in addition, oxygen concentration in the metallic base layer is also 100 wt. ppm or less. In a method of manufacturing a magnetic recording medium on the base body of which the metallic base layer and ferromagnetic metallic layer are successively formed by sputtering, the impurity concentration of Ar gas used for the formation of the layer is 10 ppb or less.