Effects of excessive Zn 2+ ions on intrinsic magnetic and structural properties of Ni 0.2Zn 0.6Cu 0.2Fe 2O 4 powder prepared by chemical coprecipitation method

Abstract

Zn(OH) 2 is a kind of amphoteric compound. Therefore, for chemical coprecipitation method, the precipitation of Zn 2+ ions may be incomplete if using NaOH as precipitator. In this study, single-phase powder specimens with a nominal composition Ni 0.2Zn 0.6Cu 0.2Fe 2O 4 were prepared with chemical coprecipitation method, and the effects of excessive Zn 2+ content ( x, x = 3%, 5%, 7%, 9%) in working solution on intrinsic magnetic and structural properties were studied by vibrating sample magnetometer and X-ray diffractometer, respectively. It was found that the magnetization when H m = 398 kA/m (5000 Oe) reached a maximum when x = 5%, and then decreased with the increase of x, which was attributed to the effect of different amount of Zn 2+ in A sites on the A–B and B–B exchange interaction. Moreover, it was found that the lattice parameter was affected by the Zn 2+ and Fe 3+ ions due to their different ion radius to a certain extent.