2016 年 40 巻 1 号 p. 1-7
A design guideline for heat-assisted magnetic recording (HAMR) is presented with a view to obtaining a minimized anisotropy constant ratio Ku / Kbulk for media by using a model calculation. We investigated the relationship between the design parameters and the limiting factors of HAMR design. The parameters, namely the writing temperature Tw and recording layer thickness h, are related to the medium thermal stability factor of the limiting factor. In addition, inter-grain exchange coupling J is related to the statistical thermal stability factor. HAMR combined with shingled magnetic recording (SHAMR) has the advantage of reducing the medium thermal gradient, and increasing Tw is also effective in increasing the heat-transfer thermal gradient of the limiting factor. The combination of increasing h and SHAMR or increasing J and SHAMR can successfully reduce Ku / Kbulk. Furthermore, Ku / Kbulk can be reduced by the combination of increasing Tw and SHAMR.
