Structural, morphological and magnetic properties of Ni/NiO systems produced by a sorbitol-assisted wet chemical method

In this work, we show the sorbitol-assisted synthesis method to produce polycrystalline Ni/NiO systems with different phase proportions. The samples were prepared from heat treatment of an aqueous solution of nickel chloride and sorbitol by using a simple wet chemical approach. The produced samples were calcined at 500 °C and the characterization of the as-produced samples was performed by X-ray diffraction (XRD), Rietveld analysis and scanning electron microscopy (SEM). Magnetic properties of Ni/NiO samples were investigated by DC magnetometry technique. XRD data reveal an increase in the proportion of metallic Ni phase in the synthesis products as the quantity of sorbitol in the starting solution is increased. Multi-phase Rietveld analysis showed that the phase fractions in the samples varied from 5.9 wt% (94.1 wt%) to 22.5 wt% (77.5 wt%) for Ni (NiO) phase. SEM analyses show changes in particle shape and size when sorbitol increases. The increase in the magnetization with increasing of Ni phase content up to at 65 kOe is assigned to the increase of the ferromagnetic (FM) phase.