Title :
Magnetic and R/W properties of CoPt-SiO2 granular media
Author :
Kaitsu, I. ; Inomata, A. ; Okamoto, I. ; Shinohara, M.
Author_Institution :
Lab. of File Memory, Fujitsu Labs. Ltd., Atsugi, Japan
fDate :
7/1/1998 12:00:00 AM
Abstract :
We fabricated Co80Pt20-SiO2/Cr granular media by sputtering and studied their structure and their magnetic and read/write (R/W) properties while varying the volume ratio of CoPt to SiO2. Transmission electron microscopy (TEM) images revealed that the diameter of CoPt particles increased with an increase in volume ratio. The maximum coercivity (about 2700 Oe) was obtained at 65 vol% of CoPt. On the other hand, at over 40 vol% of CoPt media, the signal to media noise ratio (S/Nm) rapidly decreased with an increase in the volume ratio. This indicates that media with finer grains exhibit low noise. In the same way, the instability of the magnetization was diminished with an increase in volume. This instability is very sensitive to the grain size of CoPt
Keywords :
chromium; cobalt alloys; coercive force; discontinuous metallic thin films; ferromagnetic materials; grain size; magnetic recording noise; magnetic thin films; magnetisation reversal; platinum alloys; silicon compounds; sputter deposition; sputtered coatings; transmission electron microscopy; Co80Pt20; Co80Pt20-SiO2/Cr granular media; Co80Pt20SiO2-Cr; SiO2; coercivity; grain size; longitudinal recording media; magnetic properties; magnetization instability; particle diameter; read/write properties; rigid disk system; signal to media noise ratio; sputter deposition; transmission electron microscopy images; volume ratio; Chromium; Coercive force; Magnetic anisotropy; Magnetic films; Magnetic noise; Magnetic properties; Magnetic separation; Perpendicular magnetic anisotropy; Signal to noise ratio; Sputtering;
Journal_Title :
Magnetics, IEEE Transactions on
