Abstract
Magnetic properties and recording performance of thin CoPtCr-SiO 2 media were examined in relation to thermal stability. Magnetic anisotropy Ku of {(Co90Cr10) 80Pt20}89-(SiO2)11 media maintains a constant value of around 5.5 × 106 erg/cm 3, even at film thickness of 4 nm. This Ku value corresponds to the anisotropy energy of the grains Ku9 calculated by taking account of the volume fraction of about 8 × 10 6 erg/cm3, indicating a high potential to resist thermal agitation. The high Ku derives a high remanence corcivity H r of ∼ 4 kOe, even at film thickness of 8 nm, resulting in a loop squareness of nearly 1. The ratio of magnetic anisotropy energy to thermal energy KuVactkT maintained a value of more than 70, even at this thickness. The media noise at low recording density increases with decreasing film thickness below 8 nm, probably due to the thermal agitation. The recording resolution D50 showed a broad maximum of ∼ 420 kFCI at around this thickness. The reduction in Sim thickness improves recording resolution; however, it is likely that the large thermal agitation in the thin-film region degrades the recording resolution, resulting in an optimum thickness to show the highest recording resolution.
Original language | English |
---|---|
Pages (from-to) | 2461-2463 |
Number of pages | 3 |
Journal | IEEE Transactions on Magnetics |
Volume | 40 |
Issue number | 4 II |
DOIs | |
Publication status | Published - 2004 Jul 1 |
Keywords
- CoPtCr-SiO
- Coercivity
- Magnetic anisotropy
- Media noise
- Perpendicular recording media
- SiO content
- Thermal agitation of magnetization
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering