Synthesis and characterization of nanocrystals of the oxide metals, RuO2, IrO2, and ReO3

Nanoparticles of transition metal oxides with metallic properties, RuO2, IrO2, and ReO3 in the ranges 6.5-19 nm, 6-14 nm, and 8.5-32.5 nm, respectively have been prepared by soft chemical routes. The nanoparticles have been characterized by X-ray diffraction, electron microscopy, optical spectroscopy, and scanning probe microscopy. All the nanoparticles show conducting behaviour, as confirmed by tunneling conductance measurements. Magnetic properties of the nanoparticles depend on temperature as well as the particle size. In the case of ReO3 a plasmon band is observed around 520 nm, just as in copper. The band gets blue-shifted with decrease in size.