Synthesis of high permeability Cu-Mg-Zn ferrites using oxalate precursors

Abstract

We have synthesized Cu-Mg-Zn ferrites by using soft chemistry routes using oxalate precursors. Thermogravimetry (TG) studies have been carried out for selecting decomposition temperatures and weight loss measurements. These studies reveal that in all the samples, decomposition occurs in two stages. The lattice parameters show a gradually decreasing trend with increasing Mg/sup 2+/ content which is attributed to ionic radii of Cu/sup 2+/ and Mg/sup 2+/. The variation in saturation magnetization is attributed to cation migration of Mg/sup 2+/ ions to A-site. The density of samples increases gradually with increasing Mg/sup 2+/ content. This is attributed to the fact that Mg/sup 2+/ ions have less ionic radii. The sample with x=0.25 in Mg/sub x/Cu/sub (0.5-x)/Zn/sub 0.5/Fe/sub 2/O/sub 4/ has the highest permeability (/spl mu//sub i/=2181) which is sufficiently higher than that reported for ETKMG-5 ferrite (/spl mu//sub i/=550).