Nanocrystallites of pure and mixed ternary ferrites, NiFe2O4 (NiF), CuFe2O4 (CuF), CoFe2O4 (CoF), Ni0.5Cu0.5Fe2O4 (CuNiF), Ni0.5Co0.5Fe2O4 (NiCoF), and Cu0.5Co0.5Fe2O4 (CuCoF) were prepared using the auto-combustion method employing urea as a fuel. The obtained materials were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron miscroscopy (TEM), scanning electron microscopy (SEM), and BET techniques. The elemental composition of the prepared samples was checked by X-ray fluorescence (XRF) analysis. XRD indicated that the as-synthesized samples exhibit a pure spinel crystal structure. The samples have crystallite sizes ranged from 12 to 47 nm. SEM and TEM analyses showed almost spherical morphology for all ferrite particles. The M–H curves recorded using the VSM (vibrating sample magnetometer) technique showed ferromagnetic hysteresis loop for all the samples investigated. The ferrite samples were tested to be used as a supercapacitor electrode material. It is found that the measured specific capacitance of the ferrite electrodes increases according to CuCoF > NiCoF > CoF > NiCuF > CuF > NiF. The CuCoF sample showed the greatest specific capacitance of 220 F/g at discharging current density l of A/g with, an energy density of 34.72 Wh/kg and power density of 605 W/kg. The magnetic properties were also measured for the obtained nanoparticles.
