Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Tsuyoshi Onuma

Satoshi Matsunuma

Akira Yano

Kouichirou Wakabayashi

Takanobu Takayama

Tetsunori Koda

Enji Fujita

Harumi Hieida

Nobuyuki Inaba

Fumiyoshi Kirino

Katsusuke Shimazaki

Teruaki Takeuchi

Hideaki Yamanaka

A magnetic recording medium based on the perpendicular magnetic recording system includes a substrate; a back layer which is formed on the substrate and which is formed of a soft magnetic material; an in-plane magnetized layer which is formed on the back layer and which has in-plane magnetization; and a recording layer which is formed on the in-plane magnetized layer and which has perpendicular magnetization, wherein the in-plane magnetized layer has a coercivity in an in-plane direction larger than a magnetic field generated by residual magnetization in a perpendicular direction of the recording layer. The influence on the reproduction output, caused by the mirror image effect of the soft magnetic back layer is reduced in wide range recording densities, thereby improving the resolution by decreasing the difference between the reproduction outputs of the magnetic recording medium at the low recording density and at the high recording density.

Magnetic recording medium and magnetic recording apparatus

A magnetic recording medium in which the medium noise is reduced and information can be recorded at a high S/N level, and a method for producing the magnetic recording medium are provided. A magnetic recording apparatus, which is excellent in thermal stability and which makes it possible to perform the high density recording, is provided. When films are formed for the magnetic recording medium based on the perpendicular magnetic recording method, the content of B in a seed layer is made sufficiently larger than the content of B in a recording layer. Accordingly, B is diffused from the seed layer to the recording layer to facilitate the segregation of B at the crystal grain boundary in the recording layer. Thereby, the magnetic interaction between the crystal grains in the recording layer is further reduced. Thus, it is possible to greatly reduce the transition noise.

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

A recording and reproducing apparatus including a recording magnetic head and a reproducing magnetic head with their floating height lowered for high density recordation and reproduction is provided. An information recording medium is provided on which it is possible to densely record information and from which it is possible to densely reproduce information by lowering the floating height of the recording and reproducing heads. The information recording medium includes a flat substrate and a recording layer provided on the substrate. Servo patterns and management information are recorded as magnetic marks on the recording layer in advance by a servo writer or the like. Because the substrate needs no recessed and embossed patterns formed in it, the slider of the recording and reproducing apparatus can be floated at a constant floating height lower than conventionally over the whole area of the medium. During information recordation, the position of the slider is controlled on the basis of the magneto-optical signals from the magnetic marks. During information reproduction, the reproducing magnetic head controls the slider position on the basis of the magnetic leakage fields leaking from the magnetic marks.

Information recording medium with magnetic marks, recording and reproducing apparatus therefor, and head positioning method using detected magnetic leakage fields from the magnetic marks

A magnetic recording mediumcomprises, on a substrate, a soft magnetic layer, a seed layer, and a recording layerhaving an artificial lattice structure. The seed layeris formed of Pd and one selected from the group consisting of Si, B, C, and Zr. Accordingly, the magnetic exchange coupling force of the recording layerin the in-plane direction can be weakened. Minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Thus, the medium noise is reduced. That is, reproduction can be performed with a low medium noise even when information is recorded at a high density. A magnetic storage apparatus, which is provided with the magnetic recording medium as described above, can achieve an areal recording density of 150 Gigabits/square inch.

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

A magnetic recording medium comprises, on a substrate, a soft magnetic layer, a first seed layer, a second seed layer, and a recording layer having an artificial lattice structure. The first seed layer contains oxide of Fe. The second seed layer contains one of Pd and Pt, Si, and N. The magnetic exchange coupling force in the in-plane direction of the recording layer is weakened by the first seed layer and the second seed layer. Accordingly, minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Even when information is recorded at a high density, the information can be reproduced with low noise. A magnetic storage apparatus, which is provided with such a magnetic recording medium, makes it possible to achieve an areal recording density of 150 gigabits/square inch.

Growing community of inventors

Moriya, Japan

Tsuyoshi Onuma