Hitachi, Ltd.

Susumu Funamoto

Hiroyuki Suzuki

Yasushi Kitazaki

Yuzuru Hosoe

Yoshihiro Shiroishi

Akira Kato

Yoshibumi Matsuda

Kazuetsu Yoshida

Yotsuo Yahisa

Hajime Aoi

Hiroshi Tani

Koji Sakamoto

Sadao Hishiyama

Tomoyuki Ohno

Yoko Ogawa

Sakae Ohta

Shyuichi Kojima

A magnetic recording medium having a high reliability of durability against frictional motion can be ensured even in a severe rubbing test, while a low noise characteristic important for achievement of high-density recording is kept. A first underlayer made of an alloy containing Co or Ni as a main component and containing Cr and Zr simultaneously is formed over a base, a second underlayer having a rough surface is formed on the first underlayer, a third underlayer made of an alloy containing Ni as a main component and containing Cr and Zr simultaneously is formed over the second underlayer, a fourth underlayer as a film for controlling crystalline orientation is formed on the third underlayer, a magnetic layer made of an alloy containing cobalt a main component is formed over the fourth underlayer, and a protective film containing carbon as a main component is formed on the magnetic layer.

Magnetic recording medium, method for producing the same and magnetic recording apparatus using the same

In a magnetic recording medium having a ferromagnetic metallic thin film formed on a substrate as a recording film, the recording film is formed from low density crystalline particles and impregnated with lubricant among the crystalline particles to improve the corrosion-resistivity and the slide-resistivity for a magnetic head.

Magnetic recording medium and method for fabricating the same

The method of manufacturing a magnetic recording medium according to the present invention comprises a first step in which a ferromagnetic metal layer of a predetermined thickness is formed on a substrate, and a second step contiguous to said first step and in which another ferromagnetic metal layer is formed by applying a bias voltage to the substrate. Since the ferromagnetic metal layer formed at the second step is excellent in corrosion resistance, even if a protective layer such as a carbon layer incurs a pit defect when the medium is being produced or even when the protective layer is separated, the ferromagnetic metal layer in consideration will not be corroded, thus preventing any error from occurring in data recording or reproduction.

Method of manufacturing magnetic recording medium

Disclosed is a magnetic recording medium of the magnetic metal thin-film type for longitudinal recording, in which the noise is reduced by selecting the value of maximum torque L (the product of magnetic anisotropy energy Ku and magnetic layer volume v; as measured by setting the axis of rotation in plane of the medium) and the value of magnetic flux .phi. (the product of saturation magnetization Ms and magnetic layer volume v) from a range defined by 0&lt;L/(2.pi..multidot..phi..sup.2)&lt;4.times.10.sup.5 (erg/emu.sup.2).

Magnetic recording media for longitudinal recording

Growing community of inventors

Odawara, Japan

Susumu Funamoto