I. Introduction
Heat assisted magnetic recording (HAMR) [1] is the technology that will most likely surpass conventional magnetic recording (CMR) in terms of areal density capability (ADC). As bit sizes approach media grain diameters, ADC is primarily limited by media noise. In HAMR, a highly concentrated thermal spot produced by a laser is applied to the media using a near field transducer (NFT). Applying directed heat to the media brings the temperature of the grains close to the Curie point, which allows switching to occur at lower applied magnetic fields that would otherwise be possible. This means that materials with high magneto-crystalline anisotropy and small grain diameters can be used as the media in HAMR, thus leading to a higher ADC potential compared with CMR.