Thermal stability of graded exchange spring media under the influence of external fields

The thermal stability of graded exchange spring media for perpendicular recording is investigated. It is found that the energy barrier linearly decreases with the external field strength. This leads to a high thermal stability in the low frequency recording limit, where large demagnetizing fields act on the media. The attempt frequency of graded media is about a factor of 5 larger than the attempt frequency of comparable single phase media. (c) 2008 American Institute of Physics.