Preparation and magnetic property investigation of a nickel spinel ferrite-coated tetrapod-like ZnO composite

By chemical co-precipitation method the nickel spinel ferrite-coated tetrapod-like ZnO composite was prepared. The coating layer was examined by SEM, XRD and EDS, and the VSM measurement was done to study the dependence of magnetic properties of the nickel spinel ferrite-coated tetrapod-like ZnO composite on calcination temperature. Compared with bulk nickel ferrites, the composite presents a higher coercive force with lower saturation magnetization and remanent magnetization. With increase in calcination temperature, its coercive force and remanent magnetization decrease, and the saturation magnetization experiences a monotonous increase followed by a decrease. The nanostructure stability and magnetic behaviors of the nickel spinel ferrite-coated tetrapod-like ZnO composite may be associated with the doping of Zn2+ ions.