DYNAMIC HYSTERESIS OF 2-DIMENSIONAL MAGNETIC ISLANDS WITH UNIAXIAL ANISOTROPY

Frequency-dependent hysteresis for two-dimensional magnetic islands wi th uniaxial anisotropy is studied with a nearest-neighbor spin-one Isi ng model in the Bethe-Peierls approximation. A characteristic frequenc y for magnetization reversal is identified that depends on the island morphology only through the ratio theta/p of the coverage to the mean island perimeter roughness as measured by the density of unsaturated n ear-neighbor bonds. As a result, dissimilar hysteresis is predicted fo r large versus small and compact versus fractal islands. (C) 1996 Amer ican Institute of Physics.