X-ray and neutron diffraction studies on iron-substituted Z-type hexagonal barium ferrite: Ba 3Co 2− xFe 24+ xO 41 ( x=0–0.6)

Abstract

Z-type hexagonal ferrite samples in which cobalt are partially substituted with iron, Ba 3Co 2− x Fe 24+ x O 41 ( x=0, 0.2, 0.4, 0.6), were prepared by the ceramics process under a sintering oxygen partial pressure, P O 2 =21.3 or 101.3 kPa, at 1573 K. The influence of the substitution ratio and oxygen partial pressure on the complex permeability was investigated by examining the cobalt distribution over various cation sites in the Z-type structure with the neutron powder diffraction analysis performed at 294 K. The Rietveld analysis performed on the neutron diffraction patterns indicated: (a) cobalt ions occupy only four sites (12k, 4e, 2a and 2d) out of 10 possible sites, (b) only 2a site accepts substituting cobalt ions, and (c) the magnetic spins lie in the basal plane of the hexagonal structure.