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Vanadium nitride was synthesized by the reaction of VCl4 and NaNH2 at room temperature. X-ray powder diffraction could be indexed as cubic VN with the lattice constant of a=4.134Å. Transmission electron microscopy image showed particle and hollow sphere morphology. The optical properties of the as-prepared VN were investigated. [Copyright &y& Elsevier]

Ultrafine magnesium diboride (MgB2) powders were successfully synthesized at 600 °C through a solid-state reaction. The synthesis was carried out in an autoclave by using MgCl2 and NaBH4 as the reactants. The X-ray powder diffraction pattern indicates the formation of hexagonal MgB2. Transmission electron microscopy image shows that typical MgB2 crystallites are composed of ultrafine particles with an average size of 300 nm. The superconducting transition of the MgB2 sample occurs at 39 K. [Copyright &y& Elsevier]

Molybdenum carbide (Mo2C) has been synthesized via a sodium co-reduction of molybdenum pentachloride (MoCl5) and carbon tetrabromide (CBr4) in benzene at 350 °C for 12 h. X-ray diffraction (XRD) pattern indicated that the product was mainly hexagonal Mo2C with a small amount of cubic Mo2C. The lattice constants of the hexagonal Mo2C were a=3.009 and c=4.736 A˚. Transmission electron microscopy (TEM) study showed that the product consisted of slightly conglomerated particles of about 30 nm in size. [Copyright &y& Elsevier]

Nanocrystalline vanadium diboride (VB2) were successfully synthesized at 650 °C through a solid state reaction. The synthesis was carried out by reacting VCl4 with NaBH4 and Mg in an autoclave. The X-ray powder diffraction pattern indicates the formation of hexagonal VB2. An atomic ratio of B to V of 2.11:1.0 is determined from X-ray photoelectron spectra. Transmission electron microscopy image shows that typical VB2 crystallites are composed of uniform particles with the grain size in the range of 50–100 nm. [Copyright &y& Elsevier]