Bo YANG
金属学报(英文版)
A series of hexagonal close-packed (HCP) Co-W thin films were deposited by sputtering on surface oxidized silicon substrates at 300℃. A linear dependency of saturation magnetization (Ms) on W content was found up to about 9~at.~pct W, and then it underwent an increased Ms vs. W content curve as compared to the initial linear dependency. The thermal magnetization technique was used to confirm that the increased Ms behaviour is correlated to the phase separation of the Co-W thin films. The phase separation behaviour was also found to be dependent on W content and the reason was discussed in detail. Finally an interesting composition range was suggested to be about 13at.pct-17 at. pct W for the Co-W thin films, in which they exhibit much higher magnetic anisotropy energy than Co-Cr thin films and improved phase separation.
关键词:
Magnetic recording media
Gaowu Qin
材料科学技术（英文）
The microstructure and magnetic properties of Co/Cr bilayer films were examined before and after post-deposition annealing by using transmission electron microscopy (TEM), X-ray diffraction (XRD) technique and vibrating sample magnetometer (VSM). A model of grain boundary (GB) Cr-rich phase growth involving GB diffusion derived from the Cr underlayer was proposed to elucidate the kinetics of the paramagnetic Cr-rich phase growth along Co GBs within the Co layer. The correlation of the GB Cr-rich phase formation with the magnetic Co grain isolation and accordingly, improvement of magnetic properties was experimentally investigated and discussed in detail. Our analysis results are well consistent with previous micromagnetic simulations on the improvement of magnetic properties by the magnetic grain isolation. The results provide some insights into the processing-structure-property relationships of the Co/Cr bilayer films, and thus suggest that the magnetic grain isolation be feasible not only in longitudinal recording media, but also be effective in tuning the exchange coupling of magnetic grains in perpendicular recording media via the GB diffusion from underlayer and/or overlayer.
关键词:
Magnetic recording media
,
grain boundary diffusion
,
magnetic isolation
,
Co/Cr thin films
