XRD cation distribution and magnetic properties of mesoporous Zn-substituted CuFe2O4

The effect of Zn doping on magnetic properties of mesoporous CuFe2O4 has been investigated. The cation distribution amongst tetrahedral (A) and octahedral (B) sites of the lattice has been calculated analytically by X-ray diffraction (XRD), using the Bertaut method. The results reveal that these ferrites belong to the family of mixed or partially inverse spinels and Zn2+ ions occupy mainly the A site while Cu2+ ions have more tendency for the B-site. The magnetic moments estimated from cation distribution do not coincide with the magnetization data obtained from the SQUID-VSM technique. This is attributed to the core–shell structure of nanoparticles and non-collinearity of spins at the surface or spin canting in the sublattices of Zn-substituted CuFe2O4 nanoparticles. The temperature dependence of the zero field cooled (ZFC) and field cooled (FC) magnetization curves of mesoporous Cu0.75Zn0.25Fe2O4 confirms the presence of superparamagnetic phase at room temperature.