Langevin micromagnetics of recording media using subgrain discretization

Author

Schrefl, Thomas ; Scholz, Werner ; Süss, Dieter ; Fidler, Josef

Author_Institution

Inst. of Appl. & Tech. Phys., Vienna Univ. of Technol., Austria

Volume

36

Issue

5

fYear

2000

fDate

9/1/2000 12:00:00 AM

Firstpage

3189

Lastpage

3191

Abstract

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 stochastic differential equations with multiplicative 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 -255 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 1 ns and higher are observed for about 20% of the calculations. Then the system switches from the high remanent state to a metastable state where it remains trapped for several nanoseconds

Keywords

chromium alloys; cobalt alloys; digital magnetic recording; ferromagnetic materials; finite element analysis; magnetic recording noise; magnetic thin film devices; magnetisation reversal; platinum alloys; CoCrPt; Heun method; Langevin micromagnetics; Stratonovich sense; external field; finite element based micromagnetics; high speed regime; metastable state; multiplicative noise; recording media; remanent state; reversal times; space discretization; stochastic differential equations; subgrain discretization; thermally assisted switching; thin film media; Differential equations; Finite element methods; Magnetic switching; Magnetization; Micromagnetics; Stochastic processes; Stochastic resonance; Stochastic systems; Switches; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.908732

Filename

908732