Very high-density and low-cost perpendicular magnetic recording media including new layer-structure "U-Mag"

Author

Matsunuma, Satoshi ; Koda, Tetsunori ; Yano, Akira ; Yamanaka, Hideaki ; Shimazaki, Katsusuke ; Fujita, Enji ; Ota, Norio ; Nishida, Yasutaka ; Tagawa, Ikuya

Author_Institution

Dev. & Technol. Div., Hitachi Maxell Ltd., Ibaraki, Japan

Volume

41

Issue

2

fYear

2005

Firstpage

572

Lastpage

576

Abstract

We have fabricated a new layered structure, named "U-mag," for perpendicular magnetic recording media, in terms of stacked films including a very thin (2 nm) ferromagnetic (Co) intermediate layer and lattice spacing control layers. The formed medium having a 100-nm soft magnetic underlayer with high coercivity over 6 kOe and sufficient nucleation field (-1.5 kOe) shows higher signal-to-noise ratio (SNR) than a medium with a conventional Ru underlayer. The detailed microstructures of the U-mag medium were also revealed by a transmission electron microscope with an energy dispersive spectrometer. A double Co intermediate layer gave a significant improvement in the SNR compared to a single Co layer.

Keywords

cobalt; crystal microstructure; ferromagnetic materials; magnetic multilayers; magnetic thin films; nanostructured materials; nanotechnology; perpendicular magnetic recording; ruthenium; soft magnetic materials; 100 nm; 2 nm; Co; Ru; U-mag layered structure; U-mag medium microstructure; conventional Ru underlayer; double Co intermediate layer; energy dispersive spectrometer; lattice spacing control layers; perpendicular magnetic recording media; signal-to-noise ratio; soft magnetic underlayer; stacked films; transmission electron microscope; very thin ferromagnetic intermediate layer; Coercive force; Dispersion; Lattices; Magnetic films; Microstructure; Perpendicular magnetic recording; Signal to noise ratio; Soft magnetic materials; Spectroscopy; Transmission electron microscopy; Intermediate layer; perpendicular recording media; underlayer;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2004.838070

Filename

1396182