The spinel-structured ferrite was studied by using Mössbauer spectroscopy and X-ray diffraction techniques. It was found that the Mössbauer spectra consisted of two 6-line patterns which corresponded to the presence of Fe3+ at tetrahedral and octahedral sites. Atomic migration of CoFe2O4 began near to 400K, and increased rapidly with increasing temperature. This occurred to such an extent that 69% of the ferric ions at tetrahedral sites had moved to octahedral sites before a temperature of 780K was reached.

C.S.Kim, S.W.Lee, S.I.Park, J.Y.Park, Y.J.Oh: Journal of Applied Physics, 1996, 79[8], 5428-30