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

• Published in: Journal of magnetism and magnetic materials 2012-04, Vol.324 (7), p.1305-1311
• Main Authors: Li, Cong-Ju, Wang, Bin, Wang, Jiao-Na
• Format: Article
• Language: English
• Subjects: Barium ferrite; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrospinning; Exact sciences and technology; Lanthanum; Magnetic properties and materials; Magnetic properties of nanostructures; Microwave absorption; Microwave and radio-frequency interactions (excluding resonances); Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other interactions of matter with particles and radiation; Physics
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2011.11.016

Ba(1−x)LaxFe12O19 (0.00≤x≤0.10) nanofibers were fabricated via the electrospinning technique followed by heat treatment at different temperatures for 2h. 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±20nm. 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 (Hc) decreases first and then increases, while saturation magnetization (Ms) reveals an increase at first and then decreases with La3+ ions content increase. Both the magnetic and dielectric losses are significantly enhanced by partial substitution of La3+ for Ba2+ in the M-type barium hexaferrites. The microwave absorption performance of Ba0.95La0.05Fe12O19 nanofibers gets significant improvement: The bandwidth below −10dB expands from 0GHz to 12.6GHz, and the peak value of reflection loss decreases from −9.65dB to −23.02dB with the layer thickness of 2.0mm. ► La-doped BaFe12O19 nanofibers were synthesized by electrospinning technique. ► Compared to bulk, all samples exhibited a higher saturation magnetization and coercive force. ► The substitution of La3+ ions can tune the magnetic properties and electromagnetic parameters. ► The bandwidth (below −10 dB) of Ba0.95La0.05Fe12O19 nanofibers composite is obviously broadened. ► The maximum reflection loss of Ba0.95La0.05Fe12O19 nanofibers composite is −23.02 dB.