Magnetic properties, microstructure, and read-write performance of CoSiO2-Pt granular multilayer perpendicular recording media

Co layers with added SiO₂ were applied to Co-Pt multilayer media to enhance the grain isolation and reduce the media noise. Typical magnetic properties of the media with 0.29 nm Co layer thickness and 0.12 nm Pt layer thickness were the coercivity H_c=6.2 kOe, the saturation magnetization M_s=540 emu/cm³, squareness S=1.0, the slope parameter α=1.6, the nucleation field H_n=-2.5 kOe, and the perpendicular anisotropy energy K_u=6.0×10⁶ erg/cm³. Average grain size and grain boundary of that media were 6.6 nm in diameter and about 2 nm in width, respectively. The media exhibited both excellent recording performances and good thermal stability.