Orientation dependence of the dynamic coercivity of Stoner-Wohlfarth particles

Author

Harrell, J.W.

Author_Institution

Dept. of Phys. & Astron., Alabama Univ., Tuscaloosa, AL, USA

Volume

37

Issue

1

fYear

2001

fDate

1/1/2001 12:00:00 AM

Firstpage

533

Lastpage

537

Abstract

The time dependence of the remanent coercivity for noninteracting Stoner-Wohlfarth particles with uniaxial anisotropy has been calculated numerically as a function of easy axis angle and distribution width. The results have been interpreted in terms of a simplified effective energy barrier function of the form ΔE=CKV(1-H/H₀)ⁿ and a modified Sharrock equation. For a system with identical easy axis angles, Sharrock law behavior occurs at all angles over a wide range of times with C=1 and n a function of angle. For a distribution of easy axes, Sharrock law behavior also occurs with C=1 and n≈1.5 for squareness values ranging from random to at least 0.98. The dependence of the energy barrier on field and easy axis angle is compared with the Victora expansion and with the Pfeiffer model

Keywords

coercive force; magnetic anisotropy; magnetic particles; magnetisation reversal; remanence; thermal stability; Pfeiffer model; Stoner-Wohlfarth particles; Victora expansion; distribution width; dynamic coercivity; easy axis angle; modified Sharrock equation; orientation dependence; remanent coercivity; simplified effective energy barrier function; squareness values; uniaxial anisotropy; Anisotropic magnetoresistance; Coercive force; Energy barrier; Equations; Extraterrestrial measurements; Magnetic field measurement; Magnetization reversal; Metastasis; Thermal stability; Time measurement;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.914374

Filename

914374