Wd Media (Singapore) Pte. Ltd.

Wd Media, LLC

Koichi Wago

Yoshiaki Sonobe

Teiichiro Umezawa

Takahiro Onoue

A method for manufacturing a magnetic recording medium includes the steps of (a) forming a perpendicular magnetic recording layer and (b) applying an ion beam to regions between tracks of the perpendicular magnetic recording layer so as to form separation regions for magnetically separating the tracks from each other. In the step (a), a continuous film layer composed of a multilayer film is formed, and CoB layers and Pd layers are laminated in the multilayer film. In the step (b), the CoB layers and the Pd layers are melted by the ion beam so as to form an alloy of metals contained in the CoB layers and the Pd layers to thereby form the separation regions.

Method for manufacturing magnetic recording medium

A method for manufacturing a magnetic recording medium for perpendicular magnetic recording includes the steps of forming a first magnetic layer which has magnetic crystal grains exhibiting perpendicular magnetic anisotropy and nonmagnetic substances for magnetically separating the magnetic crystal grains from each other at grain boundaries of the magnetic crystal grains, forming a second magnetic layer which has magnetic grains exchange-coupled to the magnetic crystal grains, a grain boundary width of the magnetic grains being smaller than a grain boundary width of the magnetic crystal grains, and forming separation regions which magnetically separate tracks from each other in regions between the tracks of the magnetic recording medium in at least the second magnetic layer. The separation regions are disposed substantially only in the second magnetic layer of the first magnetic layer and the second magnetic layer.

Magnetic recording medium having patterned auxiliary recording layer and method for manufacturing such magnetic recording medium

A magnetic recording medium () has a substrate () and a perpendicular magnetic recording layer () formed over the substrate (). The perpendicular magnetic recording layer () has a granular layer () in which a magnetic signal is recorded and a continuous film layer () magnetically coupled to the granular layer (). The continuous film layer () has hard magnetic portions () formed in positions corresponding to the recording regions where magnetic signals are recorded in the granular layer () and magnetic shield portions () formed between the hard magnetic portions (), each having a magnetization curve whose slope is larger than those of the hard magnetic portions in the region where the applied magnetic filed is zero when the magnetization curve is measured, and each having a residual magnetic polarization smaller than those in the hard magnetic portions.

Magnetic recording medium, magnetic recording medium manufacturing method, and magnetic disk

A magnetic recording medium for perpendicular magnetic recording includes a substrate, a granular layer having magnetic crystal grains exhibiting perpendicular magnetic anisotropy and nonmagnetic substances for magnetically separating the magnetic crystal grains from each other at grain boundaries of the magnetic crystal grains, and a continuous film layer having magnetic grains to be exchange-coupled to the magnetic crystal grains, the grain boundary width of the magnetic grains being smaller than that of the magnetic crystal grains, wherein separation regions for magnetically separating tracks from each other are disposed in regions between the tracks of the magnetic recording medium in at least the continuous film layer.

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San Jose, CA, United States of America

Koichi Wago