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Nano-crystalline vanadium disilicide was successfully synthesized using vanadium tetrachloride and silicon as starting materials via reduction–silication route at 650 °C in the molten salt solution of magnesium chloride and sodium chloride in an autoclave. X-ray powder diffraction patterns indicated that the product was hexagonal VSi2 (a=4.572 A˚, c=6.372 A˚). Transmission electron microscopy images showed that the particle size of the product was in the range of 40–60 nm in diameter. There was a strong absorption peak at 271 nm in the UV-Vis absorption spectra. The oxidation of nano-crystalline VSi2 began to proceed at the temperature of 400 °C in air. But the product had high thermal oxidation stability below 1000 °C. It can be used as an antioxidation coating material. [Copyright &y& Elsevier]

Abstract: Nanocrystalline chromium nitride (CrN) has been synthesized by reacting metallic chromium (Cr) powder with sodium azide (NaN3) at the temperature range of 450–550°C. The samples were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectra (XPS) and transmission electron microscopy (TEM). This work shows that it is very simple to synthesize CrN nanocrystalline and opens a wide route towards synthesis of other metallic nitrides. [Copyright &y& Elsevier]