Development of Media Nanostructure for Perpendicular Magnetic Recording

抄録

  The review covers the research and development of perpendicular media nanostructure focusing on the recording layer. The recording layer material includes the Co-alloys with hcp structure, the magnetic multilayers, and the alloys with ordered structures that have high magneto-crystalline anisotropies (K_u). The technologies of underlayer or interlayer for aligning the easy magnetization axis of magnetic crystal grain perpendicular to the film plane are briefly reviewed including the high K_u magnetic materials for future recording media.

  Observations of compositional and magnetization structures in sub-μm scale have played important roles in improving the recording layer. Typical data on these characteristics are explained in relation to the media structure improvements. Considering that high K_u magnetic materials will be employed in future recording media, basic experimental results related in controlling the easy magnetization axis and in keeping the surface flatness of L1₀-ordered magnetic materials are explained. Future possibilities for increasing the areal density beyond 1 Tb/in² by improving the magnetic material and the nanostructure of recording layer are also discussed.