ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Magnetic after-effect measurements were performed on an array of etched monocrystalline disk-shaped Fe dots of thickness 1 nm and diameter 200 nm. From room temperature down to 5 K, the dependence on applied field and temperature of the relaxation rate was well described on the basis of the Néel–Brown model of magnetization reversal by a rotational Brownian motion. The distribution of anisotropy fields of the dots was deduced from the nonlogarithmic relaxation rate SH,T(t) at room temperature by using a scaling procedure. From the analysis of the field dependence of SH,T(t), the activation volume was estimated at approximately 1500 nm3, with a tendency to increase slightly for temperatures below 100 K. In terms of micromagnetic reversal mechanisms, such a small value indicates that a noncoherent reversal mode occurs in the dots. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.370842
