Line profile analysis and low temperature AC susceptibility of Cu-Zn ferrites

The Cu1-xZnxFe2O4 (x = 0, 0·2, 0·4, 0·6, 0·8, 1.0) samples were prepared using double sintering ceramic method by adding Zn2+ at different concentration. The X-ray line profile analysis were carried out to confirm the spinel phase formation as well as to know the (%) strain in the crystal. The real and imaginary part of a.c. susceptibility measured from 77K to room temperature. The high temperature peak corresponds to magnetic blocking of individual particles, while the low temperature peak is attributed to surface spin-glass freezing. To prove the dynamics of the spin (dis)order in both regimes of freezing and blocking, the frequency dependent ac susceptibility is investigated under a biasing dc field. The frequency shift in the ''frozen'' low-temperature ac susceptibility peak is fitted to a dynamic scaling law which indicates a spin-glass phase. Exchange bias is turned on at low temperature which signifies the existence of a strong core-shell interaction.