Effects of copper content on the structural and magnetic properties of spinel (Co,Cu)Fe2O4 ferrites

Spinel Co-Cu ferrites with the nominal composition Co1-x Cu (x) Fe2O4 ferrites (x = 0.0-0.4 with steps of 0.1) were prepared by a chemical coprecipitaiton and sintering process, and their structural and magnetic properties were studied by using XRD, TGA-DTA, FTIR, SEM and VSM analyses. All the specimens prepared are single phase after sintering at 900 A degrees C for 5 h, and nearly no change of lattice parameter is found. The study of grain size shows that suitable amount of Cu substitution is favorable for the growth of grains, while too much Cu substitution inhibits the growth of grains instead. Also found is that with the increase of x, the saturation magnetization decreases continuously from 76.6 (x = 0.0) to 59.0 emu/g (x = 0.4), while the coercivity exhibits a first decreasing but then increasing tendency.