MAGNETIC CORRELATIONS IN THE REMANENT STATE OF NANOCRYSTALLINE AND MICROCRYSTALLINE BARIUM HEXAFERRITE PARTICLES STUDIED BY NEUTRON DEPOLARIZATION

In this paper the results of a neutron depolarisation study of the mag netic correlations in the remanent magnetised state of nano- and micro crystalline barium hexaferrite particles are presented. It appeared t hat in the virginal state of both systems the particles form stacks. U pon increasing magnetisation, correlations between particles and stack s/clusters of particles are induced. For the nano-crystalline ferrites these correlations are broken in the magnetisation reversal process, whilst they maintain for the macro-crystalline ferrites. This differen ce is likely to be caused by different interaction strengths for both types of ferrites.