Title :
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
fDate :
7/1/2001 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
