Preparation and Magnetic Properties of Cu Ni Al Ferrite Nanoparticles and Polypyrrole/Cu0.5Ni0.5Al0.3Fe1.7O4 Composite

Nanostructure copper nickel aluminum ferrite samples (Cu0.5Ni0.5AlxFe2-xO4, x=0, 0.1, 0.2, 0.3 and 0.4) have been synthesized by using the citrate precursor technique. Then, a PPy/Cu0.5Ni0.5Al0.3Fe1.7O4 composite sample has been prepared by polymerization of polypyrrole (PPy) monomer in the presence of Cu0.5Ni0.5Al0.3Fe1.7O4 nanoparticles. The characterizing techniques used in the present investigation are X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and vibrating sample magnetometer (VSM) measurements. The results have revealed the pure formation of the desired ferrite nanoparticles. The formation of PPy has been evidenced by FTIR. The lattice constant and the theoretical density Dx have been found to decrease by increasing the aluminum content, whereas the Debye temperature and the elastic moduli have increased. The SEM image of the composite has obviously clarified that the ferrite particles are dispersed nearly homogeneously in the polymer matrix. The hysteresis loops of all samples have proved that they can be classified as soft magnetic materials. Moreover, the saturation magnetization Ms of the ferrite series has been found to decrease with the increase in Al content and also has further decreased in the composite as expected. The coercivity Hc has low values in general. Moreover, its value of the composite is higher compared to that of the pure Cu Ni ferrite because the PPy increases the surface anisotropy, whereas it is almost equal to the coercivity of the Al containing ferrites, indicating some similarity of introducing Al and PPy to the material from the perspective of interruption of the ferrimagnetic order. The low coercivity of the samples are required in important devices which depend on soft magnetic materials such as switching devices and high frequency transformers.