Investigation of Dielectric Properties of Ni(CuAg)Fe2O4/Graphene Nanocomposite

Abstract

In this study, a novel nanocomposite for the improvement of dielectric properties was prepared. Nickel ferrite was synthesized successfully using chemical wet Co-precipitation route. The synthesized nanocomposite is of nickel ferrite Ni1−x(CuAg)xFe2O4 doped with silver ions and copper ions (where x= 0,0.25,0.5) and decorated on graphene nano sheets using dispersive method. The Ni0.5(CuAg)0.5Fe2O4@Graphene nanocomposite is used for the first time to improve dielectric properties. It has been demonstrated that Ni0.5(CuAg)0.5Fe2O4@Graphene nanocomposite has better dielectric constant as compared to nickel ferrite. Various techniques have been used to characterize the doped nanoparticles and nanocomposites mainly Scanning electron microscopy (SEM), X-Ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Impedance analyser. XRD pattern of the prepared nanoparticles show that all the samples show a single phase cubic spinel structure without any impurity. XRD of nanocomposites show that there is no structural changes observed with the addition of graphene. SEM images reveal that prepared nanoparticles are spherical in shape and no agglomeration was observed. SEM images of nanocomposites clearly show that ferrites nanoparticles were homogenously decorated along the surface of the graphene sheets. Impedance analyser was used to investigate the dielectric properties of Ni1−x(CuAg)xFe2O4 nanoparticles and nanocomposites. It was observed that dielectric constant, dielectric loss, tangent loss and AC conductivity increases in doped nanoparticles due to the increase in number of the charge carriers. Graphene nanocomposites show further enhancement in all the dielectric properties due to the conductive nature of graphene. Impedance of the doped nanoparticles was also decreases because doping of copper and silver promotes the hopping mechanism of electrons. Graphene nanocomposites show further decrease in impedance values as graphene provides conductive network near the grain boundaries which ensures the fast and sustained transportation of electrons.