Fabrication of Patterned Magnetic Nanomaterials for Data Storage Media

Patterned media (PM) for magnetic information storage have received increased attention in recent years as the primary candidate for 1 Terabit/in2 or higher recording density for computer hard disk drives. A PM consists of a periodic array of well-defined magnetic islands, each of which can store one bit of data. In the simplest scheme, the structures could be magnetic pillars and dots with a single easy axis of magnetization. The direction of detected magnetization by the read/write head is interpreted as a binary signal 1 or 0. Some of the main technical issues in the PM include the difficulty in fabricating small nanoisland arrays in a periodic fashion over large areas, reliability/reproducibility of magnetic bit characteristics, as well as wear and head flyability issues associated with the media surface roughness, and processing cost. This article deals with a recent investigation of various fabrication approaches, nanostructural features, and magnetic properties for the bit PM.