Heat Assisted Magnetic Recording

摘要

Perpendicular Recording has made remarkable progress in the past few years. It has recently been announced in several high-density commercial disk drive products. Areal Densities have been demonstrated at 245Gb/in{sup}2.[1] In spite of this recent progress, serious challenges remain. Jitter is experimentally observed to be the major contributor to SNR in perpendicular recording. Reducing the jitter requires that cross track correlation length and grain diameter be reduced. This reduction in grain size necessitates higher anisotropy grains in order to maintain thermal stability at higher densities. The fields to write these higher Hk grains are limited in perpendicular recording by the Bs of available materials (2.4T), the head media spacing, and the geometry of the head. For example, side shields, which are necessary to reduce adjacent track erasure, decrease the on track write field. In practical, high-density perpendicular recording fields are limited to Heff <20koe. Thus conventional perpendicular recording does not appear to be extensible beyond roughly 500Gb/in{sup}2. Alternative technologies are needed. Heat Assisted Magnetic Recording (HAMR) is a promising alternative to increase magnetic recording areal densities beyond 500Gb/in{sup}2.