Abstract:The thermal treatment method was employed to prepare nickel-cobalt oxide (NiO/Co 3 O 4 ) nanoparticles. This method was attempted to achieve the higher homogeneity of the final product. Specimens of nickel-cobalt oxide were characterized by various experimental techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). X-ray diffraction results showed that there was no crystallinity in the predecessor, and it still had the amorphous phase. The formations of the crystalline phases of the nickel-cobalt oxide nanoparticles started from 350-500˝C, and the final products had different crystallite sizes ranging from 11-35 nm. Furthermore, the variation of DC conductivity (σ dc ), impedance, tangent loss (tgδ) and dielectric constant (ε 1 ) of the calcined specimens with frequency in the range of 10 2 -10 6 Hz was investigated. σ dc showed a value of 1.9ˆ10´6 S/m, 1.3ˆ10´6 S/m and 1.6ˆ10´6 S/m for the specimens calcined at 350, 400 and 450˝C, respectively. Additionally, a decrease in tgδ values with an increase in temperature was observed. Finally, the formed nanoparticles exhibited ferromagnetic behaviors, which were confirmed by using a vibrating sample magnetometer (VSM).