Effects of Ce3+ doping on the structure and magnetic properties of Mn-Zn ferrite fibers

Ce3+-doped Mn-Zn ferrite fibers were successfully prepared by the organic gel-thermal decomposition method from metal salts and citric acid. The composition, structure, and magnetic properties of these ferrite fibers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results show that Mn0.2Zn0.8Fe2−xCexO4 (x = 0–0.04) fibers are featured with an average grain size of 11.6–12.7 nm, with diameters ranging between 1.0 to 3.5 μm and a high aspect ratio (length/diameter). The Ce3+ ion doping has not resulted in crystal structural changes of the Mn-Zn ferrite phase and all the as-prepared ferrite fibers have a simple spinel phase structure, although this influences the morphologies of Mn0.2Zn0.8Fe2−xCexO4 ferrite fibers possibly owing to the lattice distortion and internal-stress. Both the lattice constant and grain size increase slightly with the increase of the Ce3+ ion doping content. The soft magnetic properties of Mn-Zn ferrite fibers can be improved by a small amount of Ce3+ ion doping with an increase of the saturated magnetization and a decrease of the coercivity.