Title :
Low noise FeAlSi soft magnetic under-layer for CoPtCrO double-layered perpendicular recording media
Author :
Hikosaka, Takashi ; Nakamura, Futoshi ; Oikawa, Souichi ; Takeo, Akihiko ; Tanaka, Yoichiro
Author_Institution :
Data Storage Dev. Center, Toshiba Corp., Kawasaki, Japan
fDate :
7/1/2001 12:00:00 AM
Abstract :
FeAlSi multi-layered structure successfully reduced the noise compared with a mono-layered film. Optical surface analyzer also revealed that the films did not show any clear magnetic domains of spike noise source in the whole disk. TEM image of low noise film showed wide grain boundaries between 200 to 500 nm diameter FeAlSi grain clusters. The coercivities of films were significantly reduced when they were laminated. Along with the cluster isolation effect, the interlayer magnetic coupling of the multi-layered FeAlSi films also effectively reduce the noise. Double-layered perpendicular medium with a CoPtCrO recording layer and a multi-layered FeAlSi soft under-layer showed 25.8 dB SNR at 400 kBPI and 0.36 μm read truck width, and 2.5×10-7 BER on a spin stand was achieved
Keywords :
aluminium alloys; chromium alloys; cobalt alloys; coercive force; grain boundaries; iron alloys; magnetic multilayers; magnetic recording noise; perpendicular magnetic recording; platinum alloys; silicon alloys; transmission electron microscopy; BER; CoPtCrO; CoPtCrO double-layered perpendicular recording media; CoPtCrO recording layer; FeAlSi; TEM image; cluster isolation effect; coercivities; double-layered perpendicular medium; grain boundaries; interlayer magnetic coupling; laminated films; low noise FeAlSi soft magnetic under-layer; multi-layered structure; optical surface analyzer; spike noise source; spin stand; Grain boundaries; Magnetic analysis; Magnetic domains; Magnetic films; Magnetic noise; Noise reduction; Optical films; Optical noise; Perpendicular magnetic recording; Soft magnetic materials;
Journal_Title :
Magnetics, IEEE Transactions on
