On the re-entrant magnetism in the insulating diluted spinel Co0.5Zn0.5Fe₂O₄

Disordered spinel ferrites exhibit relaxation behaviour in their Mossbauer spectra. The results of the low-field magnetisation measurements on a representative system show for the first time that the system undergoes a ferrimagnetic transition at T N and then, on cooling, enters into a cluster spin-glass state below T f with the magnetisation of different clusters randomly frozen. The observed relaxation features in the Mossbauer spectra could be related to the instability in the ferrimagnetic state at higher temperatures.