| Highly uniform cobalt oxide (Co3O4) nano-octahedra with mean edge length about 16.4± 3.1 nm have been prepared using a hydrothermal method. X-ray diffraction pattern shows the normal spinel structure with formula Co2+ (Co3+)2O4 as the only crystallographic phase. The Co3O4 nanoparticles were characterized by UV-Vis and Raman spectroscopies and its morphology was determined by scanning and high resolution transmission electron microscopies. Magnetic properties of Co3O4 nano-octahedra were determined with a MPMS SQUID magnetometer. The blocking temperature (Tb) at 8K and a slight hysteresis loop indicating a ferrimagnetic behavior were observed. The magnetic response could be explained by uncompensated surface spins of the Co3O4 nanoparticles. |
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