Reversal field versus pulse time: theoretical and experimental comparison

Author

Bertram, H. Neal ; Safonov, Vladimir L.

Author_Institution

Center for Magnetic Recording Res., California Univ., San Diego, La Jolla, CA, USA

Volume

36

Issue

5

fYear

2000

fDate

9/1/2000 12:00:00 AM

Firstpage

2447

Lastpage

2449

Abstract

A new model of reversal field versus pulse time is used to analyze measurements on elongated particles in magnetic tape. The model applies to all times and temperature and fits the data extremely well. At long times the model agrees with simple Neel-Arrhenius models, but for times less than about 0.1 ms exhibits a progressively increasing switching field. This increase is shown to be due initially to a field dependent attempt frequency. At extremely short times dynamic processes dominate and in this regime the best estimate of the damping constant is obtained. The model gives values of effective volume and anisotropy that are in agrement with nonuniform reversal in these particles

Keywords

magnetic anisotropy; magnetic particles; magnetic tapes; magnetisation reversal; Neel-Arrhenius model; anisotropy; attempt frequency; damping constant; effective volume; elongated particles; magnetic tape recording; magnetization dynamics; pulse time; reversal field; switching field; thermal fluctuations; Damping; Frequency; Magnetic analysis; Magnetic anisotropy; Magnetic field measurement; Particle measurements; Perpendicular magnetic anisotropy; Pulse measurements; Temperature; Time measurement;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.908462

Filename

908462