Langevin Micromagnetics of Recording Media using Subgrain Discretization

Thomas Schrefl, Werner Scholz, Dieter Süss and Josef Fidler

IEEE Trans. Mag., 36 (2000) 3189 - 3191

Finite element based micromagnetics is applied to study thermally assisted switching of thin film media in the high speed regime. The space discretization leads to a system of sto-chastic differential equations with multiplicate noise which is interpreted in the sense of Stratonovich and solved using the method of Heun. For a CoCrPt alloy system, an external field of 240 kA/m was found to be sufficient to switch the magnetization in less than 1 ns in about 80% of the realizations of the stochastic process. However, reversal times up to 10 ns and higher are observed for about 15% of the calculations. Then the system switches from the high remanent state to a meta-stable state where it remains trapped for several nanoseconds.

<< Back to list of publications
<< Back home

webmaster: fidler (at)
Feb. 13, 2001