Sony Corporation

Seiji Kumagai

Yoshito Ikeda

Junichi Honda

Masatoshi Hayakawa

Norikatsu Fujisawa

Eiji Nakashio

Junichi Sugawara

Hiroshi Morita

Jun Takayama

Toru Matsunaga

Kazuo Goto

Kyu Kanno

Masahiro Kikkawa

Toshihiko Yaoi

Yuji Nakano

Mineo Yorizumi

Yoshitomo Ito

Miho Suzuki

Terunobu Miyazaki

Yoshiyuki Fukumoto

Provided is a magnetic tape that includes a data band, including servo patterns, data, and a guard space. The servo patterns is formed along a longitudinal direction of the magnetic tape with an interval provided between each of the servo patterns, each of the servo patterns formed across a full width of the data band. The data is recorded between the servo patterns. The guard space is left between each of the servo patterns and the data.

Magnetic tape, magnetic tape apparatus, servo pattern recording apparatus, magnetic tape producing method, and magnetic tape recording method

A magnetic resistance element is provided that includes an upper magnetic layer, which is formed in contact with an anti-ferromagnetic layer, and at least two magnetic layers that are layered with tunnel barrier wall layers respectively inserted between the first magnetic layer and each of the at least two magnetic layers such that the magnetic resistance element has a combined resistance that corresponds to one of four predefined magnetic resistances and that can be changed to another of the four predefined magnetic resistances by applying a predefined recording magnetic field pattern to the magnetic resistance element.

Magnetic resistance element having four magnetization states and a magnetic device using the same

A magnetic tunneling element in which the tunnel current flows reliably to exhibit a stable magnetic tunneling effect. The magnetic tunneling element includes a first magnetic layer, a tunnel barrier layer formed on the first magnetic layer, and a second magnetic layer formed on the tunnel barrier layer. The tunnel barrier layer is a metal film oxidized by inductively coupled oxygen plasma and a second magnetic layer is formed on the tunnel barrier layer.

Method to manufacture magnetic tunneling elements using inductively coupled plasma

First and second magnetic layers are laminated though a tunnel barrier layer, wherein a region is formed in which change in a magnetic resistance ratio with respect to change in a voltage applied in such a manner that the second magnetic layer has a lower potential as compared with the potential of the first magnetic layer is smaller than change in a magnetic resistance ratio with respect to change in a voltage applied in such a manner that the second magnetic layer has a higher potential as compared with the potential of the first magnetic layer. Voltage is applied to the magnetic tunnel device in such a manner that the potential of the second magnetic layer is lower than that of the first magnetic layer so that dependency of the magnetic resistance ratio on the voltage is reduced. Thus, a stable tunnel current flows.

Magnetic tunnel device, method of manufacture thereof, and magnetic head

A magnetic tunneling effect device capable of displaying a so-called magnetic tunneling effect in stability, more specifically, a magnetic tunneling junction device in which a first magnetic metal layer and a second magnetic metal layer are connected together by ferromagnetic tunnel junction via an insulating layer and in which the conductance of the tunnel current is changed by the relative angle of magnetization of these magnetic metal layers. The ferromagnetic tunnel junction has a junction area of not larger than 1 10 m . For reliably controlling the junction area of the ferromagnetic tunnel junction, the insulating layer is formed by a first insulating layer for ferromagnetic tunnel junction and a second insulating layer formed on the first insulating layer for controlling the junction area of the ferromagnetic tunnel junction.

Magnetic tunneling junction device

A magnetic tunnelling element in which the tunnel current flows reliably in an insulating layer to exhibit a stable magnetic tunnelling effect. To this end, the magnetic tunnelling element at least includes a first magnetic layer, a tunnel barrier layer formed on the first magnetic layer and a second magnetic layer formed on the tunnel barrier layer. The tunnel current flows via the tunnel barrier layer between the first magnetic metal layer and the second magnetic metal layer. The surface of the first magnetic layer carrying the tunnel barrier layer has a surface roughness (Ra) of 0.3 nm or less.

Magnetic tunneling element and manufacturing method therefor

The present invention provides a magnetic head which has a magnetic circuit of a reduced size to cope with a high density recording and a preferable recording/reproduction characteristic. The magnetic head according to the present invention has at least partially a non-magnetic body,and includes: a magnetic circuit block,constituted by magnetic bodies arranged to oppose each other via the non-magnetic body,; and a magnetic tunnel element,attached to this magnetic circuit block,and having a first magnetic layer,and a second magnetic layer,which are layered via an insulation layer,. In this magnetic head, a magnetic field from a magnetic recording medium is induced to the magnetic circuit block and the induced magnetic field changes a relative angle of magnetization of the first magnetic layer,and/or the second magnetic layer,with the other magnetic layer of the magnetic tunnel element

Magnetic head with magnetic tunnel element in which induced magnetic field changes relative angle of magnetization which affects tunnel current

A novel magnetic tunnel device capable of displaying a magnetic tunnelling effect in stability and with high sensitivity even to an external magnetic field of a weak intensity. The magnetic tunnel device 1 has a layered structure including a first magnetic layer 2, a granular layer 3 layered on the first magnetic layer 2 and a second magnetic layer 4 layered on the surface of the granular layer 3 opposite to its surface carrying the first magnetic layer 2. The granular layer 3 has a granular structure which is made up of a magnetic metal phase 7 and an insulating phase 8. The first magnetic layer 2 and/or the second magnetic layer 4 of the magnetic tunnel device is formed of a ferromagnetic material having soft magnetic properties. The current is supplied in the layering direction of the layered structure.

Magnetic tunnel device

A thin film type magnetic head that electromagnetic conversion efficiency is improved by making gradually magnetic resistance larger with approaching to a magnetic gap can be provided. There is disclosed a magnetic head including a pair of magnetic core half members having nonmagnetic substrates and magnetic metal films formed on the nonmagnetic substrates and a coil formed at a concave part by a thin film forming process, the pair of magnetic core half members being jointed to each other opposite to each other through a magnetic gap formed between the respective magnetic metal films, the concave part formed on the surface formed by joining at least one of the magnetic metal films and the other magnetic metal film, wherein assistant cores consisting of magnetic materials are joined on the side of the surface by joining a pair of nonmagnetic substrates and the magnetic metal films are formed connected with the assistant cores.

Magnetic head

A method of manufacturing a magnetic head by bonding a pair of magnetic cores to each other, wherein a residual stress in the magnetic cores upon bonding them together is controlled so that a permeability of the magnetic cores in the vicinity of a magnetic recording medium sliding surface of the magnetic cores may become maximum. Accordingly, the residual stress in the magnetic cores is controlled so that the permeability of the magnetic cores may surely become maximum after forming the magnetic head, thereby ensuring a superior reproduction efficiency of the magnetic head.

Manufacturing method for magnetic head

A rotary magnetic head apparatus is provided which is capable of reliably supplying DC power for driving to an active-type reproducing head provided within a rotary drum and which is capable of taking the reproductive output signal of the active-type head to the outside of the drum. The rotary magnetic head apparatus includes a fixed drum, a rotary drum which is rotatable with respect to the fixed drum, an active-type reproducing head, disposed on the rotary drum, for reproducing information from a magnetic tape, a constant-current circuit, disposed on the rotary drum, for supplying a constant current for driving the head to the active-type reproducing head, a noncontact signal transmission device for taking the reproductive output signal which is output when the active-type reproducing head reproduces information from the magnetic tape to the outside of the rotary drum, and a sliding-type contact device for supplying external DC power to the constant-current circuit.

Rotary magnetic head apparatus with circuitry for driving head and

In a magnetic head having a pair of magnetic cores defining a magnetic gap in-between, a side of each magnetic core facing a recording medium is formed of a single-crystal ferrite, with the remaining portions of each magnetic core being formed of poly-crystal ferrite. The surface of the magnetic core facing the recording medium and the abutment surface of the magnetic core are the {100} plane and the {100} plane of the single-crystal ferrite, respectively. The magnetic head has excellent abrasion resistance and electro-magnetic conversion characteristics.

Magnetic head core arrangement having medium facing surface sides formed

A magnetic head has a pair of magnetic core substrates formed of an oxide magnetic material, at least one of the magnetic core substrates having a gap film formed on an abutment surface thereof, the pair of magnetic core substrates being abutted to each other on the gap film as abutment surfaces, having a magnetic gap formed between them. The gap film is formed of platinum, the platinum group, or an alloy consisting mainly of platinum or the platinum group. The pair of magnetic core substrates are bonded to each other to be integrated into one unit by a non-magnetic glass. The magnetic gap has a track width of not greater than 50 .mu.m. The gap film has a thickness of not greater than 150 nm. The magnetic head includes a pair of magnetic core substrates formed of an oxide magnetic material, at least one of the magnetic core substrates having a gap film formed on an abutment surface thereof, the pair of magnetic core substrates being abutted to each other on the gap film as abutment surfaces, having a magnetic gap formed between them. The gap film is selectively formed of Cr or an alloy consisting mainly of Cr, Ti or an alloy consisting mainly of Ti, or Ta.sub.2 O.sub.5 or an oxide consisting mainly of Ta.sub.2 O.sub.5. At least one of the pair of magnetic core substrates has its abutment surface inversely sputtered and then has a gap film formed thereon.

Growing community of inventors

Miyagi, Japan

Seiji Kumagai