Neutron Diffraction Studies of Zinc Ferrite and Nickel Ferrite

The chemical and magnetic structures of zinc ferrite and nickel ferrite have been investigated at room temperature by means of neutron diffraction. In agreement with previous x-ray investigations zinc ferrite has been found to possess a completely regular spinel structure with an oxygen parameter of 0.385±0.002. The diffraction peaks show no evidence of coherent magnetic scattering, whereas the background exhibits normal paramagnetic diffuse scattering. This eliminates the possibility of an antiferromagnetic structure at room temperature. In the case of nickel ferrite, calculated intensities based upon an inverted structure and the Néel model of ferrimagnetism are in good agreement with the observed intensities.