Structural and Magnetic Characterization of Cobalt Ferrite Nanofibers Produced by Electrospinning Method

Cobalt ferrite with the general formula of CoFe۲O۴ has unique magnetic properties such as high magnetocrystalline anisotropy, high coercive field, intermediate saturation magnetization, and excellent physical and chemical stability. Moreover, the use of nanofibers in the field of magnetic materials has an increasing trend due to their high surface to volume ratio, low weight, high porosity, and considerable shape anisotropy. In this research, cobalt ferrite nanofibers were produced with different diameters via electrospinning using a solution containing ۸ wt% polyvinylpyrrolidone by optimizing the applied voltage. Based on the results of energy dispersive spectroscopy (EDS), the presence of Fe, O and Co elements in the structure of cobalt ferrite nanofibers was confirmed. Also, the results of X-ray diffraction (XRD) analysis showed that cobalt ferrite nanofibers are formed in a single phase after calcination at ۸۰۰ °C. Field emission scanning electron microscopy (FE-SEM) images showed that by optimizing the applied voltage between nuzzle and collector, the average diameters of cobalt ferrite nanofibers were altered between ۸۶ nm and ۱۷۱ nm. According to vibrating sample magnetometry (VSM) saturation magnetization, residual magnetization, and coercive field of the optimized sample were measured as ۸۵ A.m۲/kg, ۶۱ A.m۲/kg and ۱.۳۲×۱۰۵ A/m, respectively. First-order reversal curve (FORC) results showed that by increasing the average diameter of the fibers, magnetostatic interaction raises. Based on the results of this research, production of cobalt ferrite nanofibers using electrospinning method is feasible. Compared to similar studies, higher values of saturation magnetization and coercive field were obtained in this work.

کلیدواژه ها:

Nanofibers ، Cobalt Ferrite ، Electrospinning ، Magnetic ceramics ، Nanomaterials.