This ferrite was studied by using X-ray diffraction, vibrating-sample magnetometry and Mössbauer spectroscopy. The crystal structure for this system was of spinel-type, and the lattice constants obeyed Vegard's law. The Néel temperature decreased linearly with the Ga concentration: thus suggesting that the super-exchange interaction Co-O-Fe link was stronger than that for the Ga-O-Fe link. The atomic migration of CoGa0.1Fe1.9O4 began near to 350K and increased rapidly, with increasing temperature, to such a degree that 73% of the ferric ions at A-sites had moved to B-sites below 700K.

Atomic Migration in Co(Ga,Fe)2O4. S.W.Lee, D.H.Kim, S.R.Hong, S.J.Kim, W.C.Kim, S.B.Kim, C.S.Kim: IEEE Transactions on Magnetics, 1999, 35[5], 3418-20