Magnetic and Microwave Absorbing Properties of Electrospun Ba(1−x)LaxFe12O19 Nanofibers

Abstract Ba (1− x ) La x Fe 12 O 19 (0.00≤ x ≤0.10) nanofibers were fabricated via the electrospinning technique followed by heat treatment at different temperatures for 2 h. Various characterization methods including scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and microwave vector network analyzer were employed to investigate the morphologies, crystalline phases, magnetic properties, and complex electromagnetic parameters of nanofibers. The SEM images indicate that samples with various values of x are of a continuous fiber-like morphology with an average diameter of 110±20 nm. The XRD patterns show that the main phase is M-type barium hexaferrite without other impurity phases when calcined at 1100 °C. The VSM results show that coercive force ( H c ) decreases first and then increases, while saturation magnetization ( M s ) reveals an increase at first and then decreases with La 3+ ions content increase. Both the magnetic and dielectric losses are significantly enhanced by partial substitution of La 3+ for Ba 2+ in the M-type barium hexaferrites. The microwave absorption performance of Ba 0.95 La 0.05 Fe 12 O 19 nanofibers gets significant improvement: The bandwidth below −10 dB expands from 0 GHz to 12.6 GHz, and the peak value of reflection loss decreases from −9.65 dB to −23.02 dB with the layer thickness of 2.0 mm.