Magnesium-zinc ferrite with copper substitutions

Abstract
The effects of Mg substitution by Cu on the properties of MgZn ferrites sintered at low temperature are investigated. The densification of MgCuZn ferrites is dependent upon Cu content in the composition Mg_0.5-xCu_xZn_0.5Fe₂O₄ + 0,5 MgO. From the sintering experiments carried out between 800 and 1100° C it was established the optimum amount of CuO (x = 0.3) which is sufficient to promote sintering at low temperature (1050°C) and to yield a dense material (4,5 g/cm³). It was evidenced a break in the resistivity for x > 0,3 when it decreases by four orders of magnitude. The strong dependence of the material parameters on the Cu ions content is consistent with the microstructural changes induced by copper ions which favour the lattice diffusion process.