Heat Assisted Magnetic Recording on High Anisotropy Nanocomposite Media

Abstract

The tremendous increase in magnetic areal density has been largely responsible for the proliferation of hard disk drive recording into new applications and markets. The superparamagnetic limit imposes a signal-to-noise ratio, thermal stability, and writability tradeoff that limits the ability to continue to scale traditional magnetic recording technology to higher storage densities. Heat assisted magnetic recording (HAMR) offers a new degree of freedom with elevated writing temperature that holds the promise of extending the areal density of magnetic data storage. By temporarily heating the media during the recording process, the media coercivity can be lowered below the available applied magnetic write field, allowing higher media anisotropy and therefore smaller thermally stable grains. The heated region is then rapidly cooled in the presence of the applied head field where transition is recorded. With a tightly focused laser beam heating the media, the write process is similar to magneto- optical recording, but in a HAMR system the readout is performed with a magneto-resistive element.