Showa Denko K.k.

Kabushiki Kaisha Toshiba

Tohoku University

Ken Inoue

Gohei Kurokawa

Haruhisa Ohashi

Akira Kikitsu

Tomoyuki Maeda

Akihiko Takeo

Migaku Takahashi

Kenji Shimizu

Shin Saito

Kota Hasegawa

A magnetic recording medium includes a non-magnetic substrate on which at least a soft magnetic underlayer, an orientation control layer, a perpendicular magnetic layer, and a protective layer are disposed. The perpendicular magnetic layer includes first to fourth magnetic layers. A first exchange coupling control layer is disposed between the first magnetic layer and the second magnetic layer. A second exchange coupling control layer is disposed between the second magnetic layer and the third magnetic layer. Following relations are satisfied where Kuis a magnetic anisotropic constant of an i-th magnetic layer, Msis a saturation magnetization of the i-th magnetic layer, and tis a film thickness of the i-th magnetic layer, Ku&#x3e;Ku, Ku&#x3e;Ku, Ms&#xd7;t&#x3e;Ms&#xd7;t, Ms&#xd7;t&#x3e;Ms&#xd7;t, Ku&#x3c;Ku, and Ms&#xd7;t&#x3c;Ms&#xd7;t.

Magnetic recording medium and magnetic recording and reproducing apparatus

A method of manufacturing a magnetic recording medium, includes at least: forming an orientation control layerthat controls orientation of an immediately above layer thereof on a non-magnetic substrate; and forming a perpendicular magnetic layerin which an easy axis of magnetization is mainly perpendicularly orientated to the non-magnetic substrate, in which the forming of the orientation control layerincludes forming a granular layer having a granular structure that includes Ru or a material in which Ru is a main component and an oxide having a melting point which is greater than or equal to 450&#xb0; C. and less than or equal to 1000&#xb0; C., by a sputtering method, and the forming of the perpendicular magnetic layerincludes growing crystal grains to form columnar crystals that are continuous in a thickness direction together with crystal grains that form the orientation control layer

Method of manufacturing magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus

A method for manufacturing a magnetic recording medium is provided. An orientation control layer is deposited on a non-magnetic substrate to control an orientation of a layer located directly thereon, and a perpendicular magnetic layer whose easy axis of magnetization is mainly oriented perpendicular to the non-magnetic substrate is deposited thereon. In depositing the orientation control layer, a first granular structure layer containing Ru or a material mainly made of Ru and a first oxide having a melting point of 1000 degrees C. or lower are deposited by sputtering. In depositing the perpendicular magnetic layer, a second granular structure layer containing magnetic particles and a second oxide having a melting point of 1000 degrees C. or lower are deposited by sputtering, and the magnetic particles are grown so as to form a columnar crystal continuing in a thickness direction. The columnar crystal includes crystal grains constituting the orientation control layer.

Method for manufacturing magnetic recording medium, magnetic recording medium and magnetic recording and reproducing apparatus

According to one embodiment, there is provided a thin magnetic film having a negative anisotropy of &#x2212;6&#xd7;10erg/cmor less and including, on at least a nonmagnetic substrate, at least one seed layer made of a metal or metal compound, a ruthenium underlayer for controlling the orientation of an immediately overlying layer, and a magnetic layer having negative anisotropy in the normal line direction perpendicular to a surface of the magnetic layer and mainly containing Co and Ir, wherein the additive element concentration of Ir in the magnetic layer is 10 (inclusive) to 45 (inclusive) at %.

Thin magnetic film, method of manufacturing the same, and high frequency oscillator, magnetic head, magnetic recording medium, and magnetic recording/reproducing apparatus using thin magnetic film

Growing community of inventors

Ichihara, Japan

Ken Inoue