NiCrx Fe2-x O-4 ferrite nanoparticles and their composites with polypyrrole: synthesis, characterization and magnetic properties

摘要

Nanocrystalline nickel chromium ferrite (NiCr (x) Fe2-x O-4, x = 0.1, 0.2) have been prepared by the chemical co-precipitation method. Half of the samples have been sintered at 620(a similar to)C and the other at 1175(a similar to)C. Then polypyrrole (PPy)-NiCr (x) Fe2-x O-4 composites have been synthesized by polymerization of pyrrole monomer in the presence of NiCr (x) Fe2-x O-4 nanoparticles. The structure, morphology and magnetic properties of the samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometer. Also, the initial magnetic permeability measurements as functions of temperature and frequency have been performed. The XRD and FT-IR studies have confirmed the well crystalline phase of ferrite nanoparticles, and the presence of amorphous PPy in the composite samples. The SEM and TEM images have obviously clarified the coating of ferrite nanoparticles by PPy in the composite samples. The hysteresis loop of the samples has proved that the samples are soft magnetic material because of their low coercivity.