Sony Corporation

Akihiko Okabe

Hiroshi Kano

Kazuhiko Hayashi

Kiyoshi Kagawa

Kenji Katori

Atsuko Suzuki

Yutaka Soda

Masatoshi Hayakawa

Hiroki Tetsukawa

Koichi Aso

Yoichi Negoro

An improvement in the corrosion resistance of a magnetoresistive head is aimed for, and a high magnetoresistivity ratio is maintained. In a magnetoresistive head equipped with, as a magnetic sensor element for detecting magnetic signals while in contact with a magnetic recording medium, a spin-valve film, which has a structure where an anti-ferromagnetic layer, a pinned layer in which the direction of magnetization is pinned in a predetermined direction by an exchange-coupling magnetic field at work between itself and the anti-ferromagnetic layer, a free layer in which the direction of magnetization changes in accordance with an external magnetic field, and a non-magnetic layer for magnetically isolating the pinned layer and the free layer are layered, the corrosion potential of the spin-valve film relative to a standard hydrogen electrode measured while immersed in a NaCl solution of a concentration of 0.1 mol/L is specified at +0.4 [V vs. SHE] or above.

Magnetoresistive head with spin valve film magnetic sensor element

The present invention is directed to a perpendicular magnetic recording apparatus and a perpendicular magnetic reproducing apparatus which can achieve high-density recording and high output reproduction. The perpendicular magnetic recording medium (2) is used which has a perpendicular magnetic film made of chiefly Co, Pt and a vertical coercive force of 1500 Oe or above. This recording medium is recorded by the magnetic head (4) of which at least the magnetic gap portion is formed of the soft magnetic thin film (3). This soft magnetic thin film (3) contains chiefly Fe and has a saturation magnetic flux density 4.pi.Ms of 19 kG or above.

Perpendicular magnetic recording and perpendicular magnetic reproducing

A magnetoresistance effect element is provided with a magnetoresistance effect film (MR film) formed of alternative laminations of magnetic layers (for example, soft magnetic layers such as Fe--Ni--Co alloy layers) which are coupled anti-ferromagnetically with each other between adjacent magnetic layers and non-magnetic layers (for example, non-magnetic layers such as Cu layers) and provided with a bias soft magnetic layer (for example, SAL layer) for application of a bias magnetic filed to the magnetoresistance effect film, where the anisotropic magnetic field (Hk) in the plane of the bias medium layer is 5 Oe.ltoreq.Hk.ltoreq.15 Oe.

Magnetoresistance effect element and magnetic field detection device

A magnetic information detecting apparatus is disclosed including a recording medium in which magnetic information is recorded and a magnetic field detection unit for detecting the magnetic information, the magnetic field detection unit having its magnetic field detecting section formed of a magnetoresistive element or a Hall element, the magnetic field detecting section surrounding peripheries of the recording medium. The recording medium has a substantially circular cross section. The magnetoresistive element has a structure of an artificial multilayer film formed by alternately stacking a conductor layer and a magnetic layer. The magnetic field detection unit has a soft magnetic body for conducting a magnetic field to the magnetic field detecting section.

Magnetic information detecting apparatus

An artificial lattice film is constituted as a multilayered film in which magnetic layers containing Cu of 1.about.50 atomic percentage and at least one component selected from Fe, Ni and Co and conductive layers are stacked one after another. By forming such an artificial lattice film on a non-magnetic substrate, a magneto-resistance effect element having excellent characteristic for use as magnetic head or magnetic sensor is provided.

Artificial lattice film and magneto-resistance effect element using the

A magnetic recording medium having a magnetic thin film of a composition expressed as (Co.sub.a Pt.sub.b M.sub.c.sup.I M.sub.d.sup.II) Ox (where a, b, c, d are atomic percent; and x is weight percent). In this composition, a+b+c+d=100, 0&lt;a, 0&lt;b.ltoreq.50, 0&lt;c.ltoreq.20, 0&lt;d.ltoreq.20, 0&lt;x.ltoreq.10. M.sup.I is at least one element selected from P, Si and Ge; and M.sup.II is at least one element selected from B, Ga, Al, In, Sn and Sb. Such magnetic thin film is capable of retaining a large coercive force regardless of its thickness and can be formed without the necessity of raising the base temperature during deposition of a magnetic layer.

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Kanagawa, Japan

Akihiko Okabe