Hitachi, Ltd.

Noritoshi Saito

Noriyuki Kumasaka

Shigekazu Otomo

Takeo Yamashita

Mitsuhiro Kudo

Hideo Fujiwara

Kazuo Shiiki

Shinji Takayama

Toshio Kobayashi

Yoshihiro Shiroishi

Ryoichi Nakatani

Yoshihiro Hamakawa

Kiminari Shinagawa

Hitoshi Nakamura

Yoshinobu Tarutani

Hiroshi Sakurai

Yokuo Saitoh

Nobuo Kobayashi

Masahiko Fujishiro

Shigeo Aoki

Niroyuki Kumasaka

A magnetic head has a superconducting quantum interference device having a ring made of a superconductive material including a Josephson junction which links to a magnetic flux generated by a magnetic recording medium, and a magnetic pole for guiding the magnetic flux generated by the magnetic recording medium or the ring made of a superconductive material arranged in parallel to a plane of the magnetic recording medium so that the magnetic flux generated by the magnetic recording medium flows into a through-hole of the ring. A magnetic recording and reproducing apparatus includes such a magnetic head, a winding to which a reproduced signal from the magnetic head is applied and the superconductive ring including the Josephson junction arranged such that the magnetic flux generated by the winding flows thereto.

Magnetic head and magnetic recording and reproducing apparatus using a

An amorphous magnetic alloy of Co-Nb-Zr system contains Co, Nb and Zr and has a composition which falls, in terms of atomic percent, within the region defined by straight lines connecting, in a ternary composition diagram assuming the total of contents of these three elements to be 100, a point (81% Co, 14% Nb, 5 Zr), a point (88% Co, 9% Nb, 3% Zr), a point (86.5% Co, 12.5% Nb, 1% Zr) and a point (81% Co, 18% Nb, 1% Zr). Disclosed also is a magnetic head having a core at least a part of which is constituted by this amorphous magnetic alloy. This magnetic head, when used in combination with a metal powder tape having a high coercive force, provides a remarkably increased recording-reproducing output.

Amorphous magnetic alloy of Co-Nb-Zr system and magnetic head made from

Disclosed is a magnetic multilayered film in which layers of Fe or of an alloy containing Fe as an essential constituent are laminated together with intermediate layers of a nonmagnetic metal. In an embodiment of the magnetic multilayered film, each of the Fe layers or each of the Fe alloy layers is epitaxially grown on at least part of each of the intermediate layers of the nonmagnetic metal. A magnetic head having the magnetic multilayered film is also disclosed. The nonmagnetic metal is at least one of those selected from the group consisting of V, Cr, Cu, Nb, W, Al and Pt.

Magnetic multilayered film and magnetic head using the same

A ferromagnetic thin film containing Fe as a main component and at least one additive element selected from the group consisting of Co, Ni, Ru, Rh, Pd, Os, Ir and Pt, in which the total content of the at least one additive element is not less than 0.1 at % and additive contents, a, b, c, d, e, f, g and h (at %) respectively of said Co, Ni, Ru, Rh, Pd, Os, Ir and Pt satisfy ##EQU1## The ferromagnetic thin film thus disclosed has a high saturation flux density of 18 KG or more, a magnetostriction constant close to zero, and excellent corrosion resistance. There is also disclosed a magnetic head using the above described ferromagnetic thin film in at least a part of a magnetic circuit thereof.

Ferrromagnetic thin film and magnetic head using it

A core burying channel is formed on the outer side surface of an air bearing rail of a floating magnetic head floating on a magnetic disk by an air-flow in a direction perpendicular to a magnetic recording medium travelling direction, and a magnetic core is buried in this core burying channel. This magnetic head can be produced easily by a production method which forms a core burying channel in a non-magnetic block, then deposits a magnetic material to the core burying channel and removes unnecessary portions of the magnetic material.

Floating magnetic head having a magnetic core buried in a channel on an

A tunnel erasing-type magnetic head having a short distance between the gaps, wherein a second core half is sandwiched between the first core half and the third core half, a magnetic gap for recording and reproducing the signals is formed between the first core half and the second core half, and a magnetic gap for erasing is formed between the second core half and the third core half, so that the second core half can be utilized for both recording and reproducing the signals and erasing the signals. The second core half is obtained by forming a thin magnetic film of a high saturation flux density on the base portion composed of a nonmagnetic material that forms the magnetic gap. The first and third core halves are also obtained by forming a thin magnetic film of a high saturation flux density on the magnetic gap surfaces of the base portions to produce performance that can be used for the magnetic recording media having high coercive force. The magnetic head has a short distance between the gaps. When used for a floppy disk apparatus, therefore, there does not develop under-erasing or over-erasing even for small disks, and the effective track width does not decrease, either. This head can be used also as the one in which an ordinary erasing head element and a recording and reproducing head element are combined together.

Magnetic head having short distance between gaps for recording

Magnetic head having an integrated recording and playback head and an

A magnetic head includes ferromagnetic amorphous alloy multi-layer films each composed of an alternate lamination of ferromagnetic amorphous alloy layers and magnetic spacer layers. The thickness of each ferromagnetic amorphous alloy layer is of 1 .mu.m to 10 .mu.m. The thickness of each magnetic spacer layer is of 0.01 .mu.m to 0.2 .mu.m. The ferromagnetic amorphous alloy multi-layer films constitute at least parts of the head core.

Magnetic head having ferromagnetic amorphous alloy multi-layered film

A magnetic head comprising a magnetic film in at least a part of a magnetic circuit, at least a part of the magnetic film being formed in contact with, or being exposed to, an oxide or oxygen at least in a heating step at 150.degree. C. or higher in a process for preparing the magnetic head is disclosed. An amorphous alloy film for the magnetic film has the following composition formula to give distinguished head characteristics without any oxidation:

Magnetic head made from amorphous magnetic film

A ferromagnetic material is composed of an iron alloy which contains 2 to 12% by weight of silicon and 5 to 25% by weight of at least one element selected from the group consisting of ruthenium, rhodium, palladium, iridium, platinum, gold and silver. This ferromagnetic material exhibits a high saturation flux density and good corrosion resistance. Excellent magnetic characteristics are obtained by a multilayered film which is obtained by alternatingly laminating the above ferromagnetic material and a spacer layer composed of other material. Further, a markedly increased recording density is exhibited by a magnetic head for perpendicular magnetic recording, when the end of the main pole is composed of the ferromagnetic material.

Ferromagnetic material and a magnetic head using the same material

A multilayered ferromagnetic amorphous alloy film is constituted by a plurality of main ferromagnetic material alloy films of a ferromagnetic amorphous alloy laminated one upon another with a spacer ferromagnetic material layer interposed therebetween, the spacer ferromagnetic material layer being of a ferromagnetic material different from the ferromagnetic alloy. Also disclosed is a magnetic head employing the above-described multilayered film for, at least, a portion of a core thereof. The multilayered film has excellent magnetic characteristics and is easily patterned.

Multilayered ferromagnetic amorphous alloy film and magnetic head

There is provided a structure of a composite type magnetic head and its manufacturing method. The composite type magnetic head comprises: two high permeability ferrite blocks with projections having nearly edged sections formed thereon; magnetic films having a high saturation flux density deposited on the side faces of the projections, the magnetic films confronting each other via a functional gap near front ends of said projections; guard films deposited over the magnetic films comprising a non-magnetic material; and non-magnetic materials filled on the guard films up to side face of the coil. This magnetic head exhibits excellent recording and reproducing characteristics. The contour effect is negligibly small. The reaction between the magnetic film and the non-magnetic material is prevented by the guard film.

Composite type magnetic head for recording and reproducing high

A magnetic film structure comprises at least one magnetic film unit wherein a plurality of main magnetic films of 0.05 to 0.5 .mu.m thickness made of a magnetic alloy containing iron or cobalt as principal constituent and having a high saturation magnetic induction of 10,000 gauss or more and a magnetostriction of 10.sup.-6 or less are laminated through intermediate magnetic films made of a magnetic material such as a nickel and iron alloy or amorphous magnetic alloy different from that of the main magnetic film and being so thin that the influence of coercive force of the intermediate magnetic film does not come out. A plurality of the magnetic film units are also laminated through non-magnetic insulating films. The magnetic film structure has high saturation magnetic induction and low coercive force.

Magnetic film structure

A magnetic head core and a method of fabricating same, wherein a magnetic circuit is constituted by a pair of magnetic films having a V-shaped cross section which face each other at each protrudent section through the gap material. The cross-sectional portion of the V-shaped film is exposed to the surface facing the magnetic recording medium. The protrusions of the magnetic film pair have tip planes parallel to each other and substantially perpendicular to the moving direction of the magnetic recording medium. The tip plane has a width defined by the line of intersection between the plane and the surface facing the magnetic recording medium in correspondence to the recording track width. At least one of the magnetic films has a window for winding an excitation coil. The magnetic film is formed on the non-magnetic protection member having a V-shaped protrusion. The magnetic head has superior recording and reproducing characteristics in a wide frequency band with less rubbing noise, high wear-resistivity and high productivity, and operates without the pseudo gap effect. The magnetic head core is fabricated through the steps of forming a coil winding groove in the gap forming plane of a non-magnetic core block, forming a number of parallel grooves perpendicularly to the winding groove so that a number of V-shaped protrusions are produced, forming a magnetic film on the surface of the protrusions, forming a gap plane after the magnetic film has been coated with non-magnetic material, and splitting the block and then combining the two core blocks to complete a magnetic head core.

Growing community of inventors

Hachioji, Japan

Noritoshi Saito