MAGNETIC-ANISOTROPY IN FINE MAGNETIC PARTICLES

In this work, the magnetization curves and the anisotropy energy constants' K are calculated for three systems of Fe3O4 fine particles using a simple model for the particle-size distribution function. The model gives a value for the mean particle diameter which is in good agreement with the value obtained from transmission electron micrographs. Also, the results for the anisotropy constant are in good agreement with those obtained from the temperature dependence of the remanent magnetization. Furthermore, Mossbauer spectra are used, together with the calculated anisotropy constants, to determine the particle-size distribution.