Kabushiki Kaisha Toshiba

Other

Hideo Ogiwara

Soichi Oikawa

Takashi Hikosaka

Futoshi Nakamura

Katsutaro Ichihara

Keiichiro Yusu

Yoshiaki Saito

Akira Kikitsu

Hiroshi Sakai

Koichiro Inomata

Kenji Shimizu

A perpendicular magnetic recording medium comprising a layer exhibiting a super paramagnetism is used as the underlying film to enable the recording medium to achieve a high density recording with a low noise.

Perpendicular magnetic recording medium and perpendicular magnetic recording-reproducing apparatus

Magnetic recording media with thermal fluctuation resistance and low noise made compatible are obtained by using as magnetic layers a combination of a first magnetic material having a first Curie point higher than the recording temperature and a second magnetic material having a second Curie point higher than the operation temperature of the apparatus and lower than the recording temperature, a combination of a ferromagnetic material having a Curie point higher than the recording temperature and an antiferromagnetic material having a Neel point higher than the operation temperature of the apparatus and lower than the recording temperature.

Magnetic recording media and magnetic recording/reproduction apparatuses

A soft magnetic laminate layer is arranged between a nonmagnetic substrate and a perpendicular magnetic recording layer so as to provide a perpendicular magnetic recording medium low in noise and capable of a high density recording. The soft magnetic laminate layer comprises a soft magnetic layer having a thickness not larger than 500 &angst; and a nonmagnetic layer, comprises a first soft magnetic layer and a second soft magnetic layer differing from the first soft magnetic layer in the crystal structure, or comprises a layer of a granular structure consisting of magnetic particles and a nonmagnetic matrix and a soft magnetic layer.

Perpendicular magnetic recording medium and magnetic recording apparatus

By using a magnetic recording medium in which the value of Hk/4&pgr;Ms calculated from the anisotropic magnetic field Hk and the saturation magnetization Ms falls within a range of more than 2 and less than 5, the resistance to the thermal decay can be improved and a magnetic recording can be achieved with a high recording resolution and a good medium S/N without increasing the head magnetic field.

Magnetic recording medium

A magnetic recording apparatus includes a magnetic recording medium including a substrate and a magnetic recording layer formed on the substrate and having a structure in which magnetic grains are dispersed in a nonmagnetic matrix, a means for recording magnetic information on the magnetic recording medium, and a means for reproducing magnetic information from the magnetic recording medium wherein the magnetic grains are separated from the substrate by a part of the matrix and form a substantially single layer parallel to the main surface of the substrate.

Magnetic recording apparatus

A magnetic element comprises a granular magnetic film which has ferromagnetic fine particles dispersed in a dielectric matrix and does not display superparamagnetism and further possesses a finite coercive force, and a ferromagnetic film. A granular magnetic film and a ferromagnetic film are stacked or arrayed along one surface of a substrate and constitutes a ferromagnetic tunnel junction film. In the ferromagnetic tunnel junction film, the granular magnetic film functions as a barrier. Of the granular magnetic film and the ferromagnetic film, by varying spin direction of one ferromagnetic film through an external magnetic field, a giant magnetoresistance effect is manifested. Such a magnetic element is characterized in that magnetoresistance change rate is large, saturation magnetic field is small, resistance of the element can be controlled to an appropriate value, performance is small in its variation and stable.

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Tachikawa, Japan

Hideo Ogiwara