The synthesis and magnetic properties of monodispersed single-domain nickel nanospheres and highly globular nanostructures of NicoreNiOshell

Abstract Monodispersed single-domain nickel nanospheres have been successfully prepared by the microwave-assisted (MW) polyol method. TEM and AFM analysis reveal that the nickel nanospheres have a size distribution in the 100–180 nm range. Highly globular nanostructures of Ni core NiO shell are achieved by oxidizing the nickel nanospheres in a flow of H 2 O 2 and the structure is studied by means of TEM, XPS, and EDAX. The single-domain magnetic structure is confirmed by MFM measurements and the ferromagnetic properties are demonstrated by VSM and SQUID studies. Surprisingly, no shift in the magnetization loop is observed despite the ferromagnet/antiferromagnet interface. This is attributed to the relatively large volume of our nanoparticles.