Dielectrically modified MWCNTs decorated nickle based spinel ferrites nanocomposites prepared via ultrasonic assisted route

The current study involved in the synthesis of nickel ferrite (NiFe₂O₄) nanoparticles using the sol-gel auto-combustion method with citric acid employed as a fuel agent. Secondly, multi-walled carbon nanotubes (MWCNTs) were incorporated, involving toluene as a functionalizing agent. The X-ray diffraction (XRD) analysis verified the development of the structural characteristics of nanocomposites. Transmission electron microscopy (TEM) images shown the successful coating of MWCNTs onto the surface of the nanoparticle matrix. Fourier transform infrared spectroscopy (FTIR) was carried out to identify the tetra and octahedral band positions in the crystal lattice. The study investigated the dielectric characteristics such as dielectric constant, dielectric loss, tangent loss, impedance's as well as the real and imaginary components of electric modulus and AC conductivity within the frequency spectrum spanning from 1 MHz to 3 GHz. These all parameters are massively changed by the linkage between the MWCNTs with spinel nanoparticle (i.e. x = 5–25 %). The hysteresis loops have confirmed the soft magnetic nature of the nanocomposite, which were measured in the applied magnetic field from of −30 to 30 KOe. The decline in magnetic behaviour down to decreased with increasing the nonmagnetic MWCNTs nanostructures. The obtained soft magnetic nature as well as the improved dielectric properties at high frequency suggested that the prepared nanocomposites can be useful for soft magnetic and high frequency device applications.