Zeheng Yang

A low temperature synthesis of crystalline B4C ultrafine powders

Abstract B 4 C ultrafine powders were successfully synthesized at 450 °C through a new co-reduction route. The synthesis was carried out in an autoclave by using BBr 3 and CCl 4 as the reactants and metallic Na as the co-reductant. The X-ray powder diffraction pattern and Raman spectra indicate the formation of B 4 C. An atomic ratio of B to C of 4.09:1.0 was determined from X-ray photoelectron spectra. Transmission electron microscopy images shows that typical B 4 C crystallites are composed of uniform ultrafine spherical and rod-like particles.

A co-reduction synthesis of superconducting NbC nanorods

NbC nanorods with diameters of 50–150 nm were successfully synthesized through a new chemical route by using NbCl5 and hexachlorobutadiene (C4Cl6) as Nb and C sources, and Na metal as the reductant at 600 °C in an autoclave. This reaction temperature is much lower than that used in traditional methods. The as-prepared NbC nanorods were characterized by x-ray powder diffraction, transmission electron microscopy and x-ray photoelectron spectra. Magnetization measurement indicated that the NbC nanorods have a superconducting transition at 12.3 K.