Critical behaviour and magnetic properties of A–B spinel ZnxCu1−xFe2O4

Polycrystalline Zn0.6Cu0.4Fe2O4 ferrites have been prepared using a solid-state reaction technique. Their structural and magnetic properties have been studied, using X-ray diffraction and Mössbauer and magnetic measurements. These results have been compared to a more general theoretical study, on ZnxCu1−xFe2O4, based on mean field theory and high-temperature series expansions (HTSE), and extrapolated with the Padé approximant method. The nearest neighbour super-exchange interactions for the intra-site and the inter-site of ZnxCu1−xFe2O4 spinel ferrites, in the range 0 ≤ x ≤ 1 , have been computed using the probability approach, based on Mössbauer data. The Curie temperature T C is calculated as a function of Zn concentration. The theoretical results obtained are in good agreement with the experimental results obtained by magnetic measurements.