Preparation and microwave-absorbing properties of silver-coated strontium ferrite with polyaniline via in situ polymerization

In this contribution, a new type of conductive and magnetic PANI/Ag/SrFe12O19 composites were synthesized via three-step method. First, SrFe12O19 was synthesized through coprecipitation reaction, then Ag/ SrFe12O19 particles were prepared via chemical plating method. Finally, PANI/Ag/SrFe12O19 composites were obtained by in-situ polymerization in the presence of Ag/ SrFe12O19. The morphologies and properties of the samples were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), UV-Visible spectrophotometry (UV-Vis) and vibrating sample magnetometry ( VSM). Results show that SrFe12O19 and Ag/SrFe12O19 particles are successfully synthesized. After coating Ag on SrFe12O19 surface, the saturation magnetization of particles decrease from 117.22 emu/g to 70.54 emu/g, whereas its conductivity increase to 107 S/cm. Meanwhile, with the introduction of Ag/SrFe12O19, the PANI/A/SrFe12O19 composites exhibit better thermal stability, electric and magnetic properties than pure PANI. Measurements of the reflection loss (R) show that PANI/Ag/SrFe12O19 composites have a good microwave absorbing property in the X band, the reflection loss of the composites is below -10 dB between 8.7 GHz and 12.1 GHz, with a minimum loss value of -14.86 at 9.98 GHz. (C) 2014 Elsevier B.V. All rights reserved.