Multilayered soft magnetic underlayers for perpendicular magnetic recording media

The soft magnetic underlayer (SUL) with high saturation magnetization in perpendicular magnetic recording media have been required essentially to achieve high recording density with high bit stability. However, stripe domain configuration caused by the induced perpendicular magnetic anisotropy and deterioration of surface smoothness in thick SULs degrades the recording performance. In this study, multilayers, with several kinds of interlayers for the SUL, were prepared in order to improve the soft magnetic properties and surface smoothness as well as reduce the media noise originated from the domain configuration.