Zn0.6Cu0.4Cr0.5Fe1.46Sm0.04O4 ferrite and its nanocomposites with polyaniline and polypyrrole: Preparation and electromagnetic properties

The nanosized Zr0.6Cu0.4Cr0.5Fe1.46Sm0.04O4 (ZCCFS(0.04)O) ferrite doped with Sin was prepared by a theological phase reaction method. These nanoparticles were further used as templates for the fabrication of polyaniline-linked ZCCFS(0.04)O and polypyrrole-linked ZCCFS(0.04)O nanocomposites via in situ polymerization method. The structures, morphology and electromagnetic property of ferrite powders and nanocomposites were characterized by X-ray powder diffractometer (XRD), transmission electron microscope (TEM), four-point probe resistivity instrument (SDY-4) and vibrating sample magnetometer (VSM). The electronic and magnetic properties of the nanocomposites are tailored by controlling the ferrite content. The pure polyaniline (PANI) and polypyrrole (PPy) films with thickness of 2 min show a maximum reflection loss of -20.93 dB and -19.68 dB at 16 GHz and an available bandwidth (frequency difference between points where the absorption is less than -8 dB) of 5.9 GHz and 6.2 GHz, respectively. When relative content of the ZCCFS(0.04)O in PANT/ZCCFS(0.04)O and PPy/ZCCFS(0.04)O composites with respect to aniline (pyrrole) monomer is approximately 20 wt%, the maximum reflection loss of -22.46 and -20.90 dB appear at approximately 14.07 and 14.05 GHz, and available bandwidth is broadened to 11.15 and 11.30 GHz, respectively. The results show that both of PANT/ZCCFS(0.04)O and PPy/ZCCFS(0.04)O composites can be used as advancing microwave absorption and shielding materials due to their favorable microwave absorption properties. (C) 2009 Elsevier B.V. All rights reserved.