Ultra high density media: gigabit and beyond

The authors review the recent advances made toward the attainment of high areal density in the Gb/in² regime. they review recent progress made in understanding the relationship between the media magnetic properties and recording characteristics such as linear resolution, transition noise, and overwrite. For high-linear-resolution media, a coercivity in the 2000-3000-Oe regime is now attainable, depending on the alloy, underlayer, and other process parameters such as substrate temperature bias. Various noise reduction schemes have been developed in recent years which are based on the decoupling of exchange interactions between magnetic grains or between multiple magnetic layers. As the bit cell size is further reduced in the Gb/in² regime, one of the main challenges will be to retain a high coercivity with decreasing grain size of the magnetic film