The 'superparamagnetic effect' presents us with a serious challenge. It is compromising our efforts to continue increasing the areal density and storage capacity of our disk drives. However, one of the most promising ways to get around this problem is by using patterned media.

In conventional media, the magnetic recording layer is a thin film of a magnetic alloy, which naturally forms a random mosaic of nanometer-scale grains which behave as independent magnetic elements. Each recorded bit is made up of many of these random grains. In patterned media, however, the magnetic layer is created as an ordered array of highly uniform islands, each island capable of storing an individual bit.

Understanding the magnetic behavior of islands with such small dimensions requires advances in both metrology tools and in the basic science of magnetic materials. One technique which is able to detect and display the magnetization of magnetic island arrays is magnetic force microscopy.

Although there are many challenges to manufacturing and using patterned media, the potential gains make it one of the most promising new technologies on the horizon for future disk drives. Hitachi is actively engaged in research to make the potential benefits of patterned media a reality.

Hitachi GST: Facing the challenge of patterned media