Dynamic Magnetic Properties of Electrospun NiZn Spinel Ferrite Nanofibers

NiZn spinel ferrite nanofibers with diameters in 50-100 nm were fabricated by electrospinning followed by thermal treatment. Deploying a rotating collector, nanofibers can achieve certain degree of alignment. The morphology phase contents, static, and dynamic magnetic properties of ferrite fibers were experimentally studied. Measured magnetic hysteresis loops indicate that the NiZn ferrite nanofibers are anisotropic with easy magnetization axis along the fiber alignment direction. The relationship between ferromagnetic resonant frequencies of nanofibers and bias magnetic fields was determined and can be described using a modified Kittel´s formula developed for polycrystalline ferrites.