Conducting, magnetic polyaniline/Ba0.25Sr0.75Fe11(Ni0.5Mn0.5)O19 nanocomposite: Fabrication, characterization and application

In this contribution, Ni/Mn doped Barium Strontium Ferrite nanoparticles (Ba0.25Sr0.75Fe11(Ni0.5Mn0.5)O-19) and conducting polyaniline/Ba0.25Sr0.75Fe11(Ni0.5Mn0.5)O-19 nanocomposite were fabricated successfully through sol-gel method and in-situ polymerization technique, respectively. Field emission scanning electron microscope (FESEM), Energy-dispersive X-ray spectroscopy analysis (EDX), X-ray powder diffraction (XRD), Mossbauer spectroscopic measurements and Fourier transform infrared spectroscope (FT-IR) analyses were adopted to confirm the composition, morphology and structure of materials. The obtained results revealed the formation of hexagonal M-type rod-shape ferrite with average particle size of about 45 nm (according to XRD data, using Debye-Scherre formula). The saturation magnetization of ferrite nanoparticles and PANI/Ferrite nanocomposite reported 44.03 and 9.85 emu/g, respectively, using vibrant sample magnetometer (VSM). Standard four-point-probe technique was employed to measure the conductivity of samples. Also optical characteristic of samples was examined by means of UV-Vis and Diffuse Reflectance Spectra (DRS) techniques which proved the formation of conducting coating of emeraldine on the surface of magnetic nanoparticles. Also the UV-vis studies indicated that the ferrite nanoparticles have an optical band gap of 1.8 eV while the values of 1.65 and 2.66 eV obtained for PANI/Ferrite nanocomposite. Finally, the microwave absorption properties of prepared nanoferrite and nanocomposite at different thicknesses (2, 3 and 4 mm) were determined at the X-band (8-12 GHz) using vector network analyzer (VNA). In this study, minimum reflection loss of -21.68 dB and maximum available bandwidth of 4.8 GHz were obtained for PANI/Ferrite (20 wt% ferrite) at the frequency of 10.6 GHz. The results suggested the fabricated nanocomposite could be a suitable candidate for decreasing radar signature. (C) 2015 Elsevier B.V. All rights reserved.