Sub-6-nm grain size control in polycrystalline thin films using synthetic nucleation layer

Abstract

A key objective in the design of recording media for hard disk drives is to tailor the grain size. A fourfold increase in the recording density from the current levels demands that the mean grain diameter be reduced from 7 to about 5.5nm, and distribution to below 15%. Traditional techniques involving dopants can realize small grain sizes but also deteriorate the structural and magnetic properties. In this study, the utility of an extremely thin synthetic nucleation layer in reducing the grain size and distribution of the recording media is demonstrated, with significant implications for other applications too.