Firstly, three different nano ferrites (MgFe2O4, NiFe2O4, and Ni0.5Mg0.5Fe2O4) were
synthesized using a combustion method. Secondly, polyaniline composites containing
small amounts of those nano ferrites were prepared using in situ chemical polymerization
method. Ferrite samples were characterized using X-ray
diffraction (XRD)
and Fourier transform infrared spectroscopy (FT-IR)
analyses. XRD analysis of ferrites
exhibited well-resolved
broad peaks, which confirm the polycrystalline and
mono-phasic
nature. FT-IR
confirmed the spinel structure of these ferrites. Polymer
nano ferrites composites were also characterized using XRD, FT-IR,
thermal analysis
(TG and DTA), and transmission electron microscope (TEM). Also, electrical
(AC conductivity, dielectric constant, dielectric loss, and complex impedance) and
magnetic properties were investigated for all nano composite samples. XRD analysis
confirmed the formation of polymer nano composites. Moreover, the absorption
bands of polyaniline were shifted in the presence of the three different ferrites, confirming
the presence of interactions between the different phases in all composites.
Additionally, different thermal stability behavior of nano composite samples was
observed, which may be attributed to the nano ferrite type and the physical interactions
nature with polymer matrix. The sample containing nano magnesium ferrite
showed the core–shell structure by TEM. The same sample exhibited the highest
values of both AC conductivity (1.01 × 10−4 ohm−1 cm−1) and magnetization saturation
(3.38 emu/g) at room temperature. In comparison with other similar composites
containing large amounts of the same ferrite, the investigated sample showed a good
magnetization saturation value and thermal stability behavior.