MnO and NiO nanoparticles: synthesis and magnetic properties

Abstract

Nanoparticles of MnO with average diameters in the 6-14 nm range have been prepared by the decomposition of manganese cupferronate in the presence of TOPO, under solvothermal conditions. Nanoparticles of NiO with average diameters in the 3-24 nm range have been prepared by the decomposition of nickel cupferronate or acetate under solvothermal conditions. The nanoparticles have been characterized by X-ray diffraction and transmission electron microscopy. Both MnO and NiO nanoparticles exhibit supermagnetism, accompanied by magnetic hysteresis below the blocking temperature (T_B). The T_B increases with the increase in particle size in the case of NiO, and exhibits the reverse trend in the case of MnO.