Magnetic anisotropy and behaviors of Fe nanoparticles

Author

Ibusuki, Takahiro ; Kojima, Seijyu ; Kitakami, Osamu ; Shimada, Yutaka

Author_Institution

Res. Inst. for Sci. Meas., Tohoku Univ., Sendai, Japan

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

2223

Lastpage

2225

Abstract

We have studied the magnetic properties of bcc-Fe fine particles with a diameter D of 3~40 nm prepared by a vapor condensation process. The particles exhibit uniaxial anisotropy of 2.0~3.0×10⁶ erg/cc which is much larger than that of bulk Fe (0.5×10⁶ erg/cc). Numerical calculations taking into account dipolar interaction and thermal agitation reproduce the particle size dependence of coercivity very well. According to the present work, magnetization reversal of Fe particles proceeds via coherent rotation for D<15~20 nm and via incoherent rotation for D>15~20 nm. It is, however, still uncertain why the magnetic anisotropy of Fe fine particles is uniaxial and so large

Keywords

coercive force; iron; magnetic anisotropy; magnetic particles; magnetisation reversal; nanostructured materials; BCC phase; Fe; Fe nanoparticles; coercivity; dipolar interaction; magnetic properties; magnetization reversal; particle size dependence; thermal agitation; uniaxial anisotropy; vapor condensation; Anisotropic magnetoresistance; Coercive force; Diffraction; Iron; Log-normal distribution; Magnetic anisotropy; Magnetic properties; Magnetization reversal; Nanoparticles; Particle measurements;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.951130

Filename

951130