Critical behaviour and magnetic properties of A-B spinel Zn _xCu_(1-x)Fe_2O_4

摘要

Polycrystalline Zn_(0.6)Cu_(0.4)Fe_2O_4 ferrites have been prepared using a solid-state reaction technique. Their structural and magnetic properties have been studied, using X-ray diffraction and Mssbauer and magnetic measurements. These results have been compared to a more general theoretical study, on ZnxCu_(1-x)Fe _2O_4, based on mean field theory and high-temperature series expansions (HTSE), and extrapolated with the Pad approximant method. The nearest neighbour super-exchange interactions for the intra-site and the inter-site of ZnxCu_(1-x)Fe_2O_4 spinel ferrites, in the range 0≤x≤1, have been computed using the probability approach, based on Mssbauer data. The Curie temperature TC is calculated as a function of Zn concentration. The theoretical results obtained are in good agreement with the experimental results obtained by magnetic measurements.