Areal density progress in magnetic recording is largely determined by the ability to fabricate low-noise, granular thin lm media with sufficient stability against thermal agitation to warrant long-term data storage. A key requirement is a medium microstructure with small, magnetically isolated grains to establish optimal macro- and micro-magnetic properties. A lower bound for the minimal average grain diameter, compatible with thermal stability, is imposed by the write field capability of the recording head. It is 10–12 nm assuming maximal writeable coercivities of 400 kA/m (5000 Oe). These are already achieved in today's state-of-the-art CoCr-based thin lm alloy media, leaving little room for further improvements and density gains based on continued grain size reduction. A threefold reduction in grain diameter, however, translating into a tenfold increase in areal density is theoretically possible if write field constraints can be overcome, allowing utilization of magnetically harder alloys. This review emphasizes materials and fabrication aspects behind media for extremely high-density longitudinal magnetic recording. Special attention is paid to thermal stability and write coercivity constraints. Various alternative media designs for extremely high-density recording beyond 40–100 Gbits/inch2 are reviewed.


Article metrics loading...

Loading full text...

Full text loading...


Data & Media loading...

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error