Synthesis of nickel-cobalt ferrite/graphene oxide nanocomposites

Abstract

Current investigation is an attempt to study the structural, optical, magnetic and dielectric properties of Ni0.5Co0.5Fe2O4/graphene oxide (NCF/GO) nanocomposites. NCF/GO nanocomposites were synthesized through the ultrasonication technique. NCF nanoparticles (NPs) and GO (with varying weight percentages of GO) were synthesized through sol–gel auto-combustion and modified Hummer’s method, respectively. The effect of nickel–cobalt ferrite NPs incorporation on graphene oxide was studied using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and Impedance Analyzer. electrical and dielectric measurements. XRD and FTIR studies showed and confirmed the formation of both spinel for the NCF NPs and amorphous graphene oxide for NCF/GO nanocomposites. The crystallite size and lattice parameter for NCF NPs were found in the range of 21–47 nm and 8.33–8.36 Å, respectively. The optical band gap was found in the range of 1.73–1.83 eV with increasing GO concentration. VSM studies revealed that the saturation magnetization (Ms) value for NCF/GO nanocomposites is found to be decreased from 59 emu/g (for NCF) to 30 emu/g (for 60 wt% of GO) with increased GO weight percentage. There was a drastic variation observed in the value of coercivity (Hc) for NCF and NCF/GO nanocomposites. However, it remains almost constant within NCF/GO nanocomposites. Dielectric studies showed the exponentially decaying nature of dielectric constant and loss tangent with logarithmic frequency. Further, the dielectric constant is increased with increasing GO content. A maximum dielectric constant is observed for NCF/GO nanocomposites with 60 wt% of GO. The AC conductivity is found to be increasing with an increase in GO weight percentage and showed its sharply increasing nature at higher frequencies.