Noise reduction in heat-assisted magnetic recording of bit-patterned media by optimizing a high/low Tc bilayer structure

Authors/others:Muthsam, O.; Vogler, C.; Suess, D.
Abstract:

It is assumed that heat-assisted magnetic recording is the recording technique of the future. For pure hard magnetic grains in high density media with an average diameter of 5 nm and a height of 10 nm, the switching probability is not sufficiently high for the use in bit-patterned media. Using a bilayer structure with 50% hard magnetic material with low Curie temperature and 50% soft magnetic material with high Curie temperature to obtain more than 99.2% switching probability leads to very large jitter. We propose an optimized material composition to reach a switching probability of Pswitch > 99.2% and simultaneously achieve the narrow transition jitter of pure hard magnetic material. Simulations with a continuous laser spot were performed with the atomistic simulation program VAMPIRE for a single cylindrical recording grain with a diameter of 5 nm and a height of 10 nm. Different configurations of soft magnetic material and different amounts of hard and soft magnetic material were tested and discussed. Within our analysis, a composition with 20% soft magnetic and 80% hard magnetic material reaches the best results with a switching probability Pswitch > 99.2%, an off-track jitter parameter σoff,80â•20 = 0.46 nm and a down-track jitter parameter σdown,80â•20 = 0.49 nm.

Language:English
Number of pages:7
Date of publication:7.12.2017
Journal title:Journal of Applied Physics
Volume:122
Number:21
Peer reviewed:true
Links:
Digital Object Identifier (DOI):http://dx.doi.org/10.1063/1.5004244
Publication Type:Article
Portal:https://ucris.univie.ac.at/portal/en/publications/noise-reduction-in-heatassisted-magnetic-recording-of-bitpatterned-media-by-optimizing-a-highlow-tc-bilayer-structure(4df8e209-b16e-4760-892e-8b662a18d68d).html