HYPERFINE PARAMETERS OF AMORPHOUS Fe6aCq6B2o PARTICLES DISPERSED IN AN ALUMINA MATRIX

Mössbauer spectra of amorphous Fe64Cr16B20 particles dispersed in an alumina matrix are compared to those of the corresponding amorphous ribbon. The slight variations between the hyperfine parameters of the granular samples are mainly assigned to disorders at the particle surface. The behaviour of the blocking temperatures versus frequency deduced from A.C. susceptibility measurements and Mössbauer spectroscopy is governed by particle interactions.