Novel zirconium nitride precursor: synthesis, decomposition pathway, and pyrolysis of [(CH3)3Si]2NH·ZrCl4

Abstract

The reaction of hexamethyldisilazane with zirconium tetrachloride furnishes an adduct, [(CH3)3Si]2NHZrCl4, which is soluble in dichloromethane. The decomposition of [(CH3)3Si]2NHZrCl4 proceeds with the elimination of trimethylchlorosilane and hydrogen chloride and is complete at 600C. The resulting powder is amorphous zirconium nitride which is highly susceptible to hydrolysis and oxidation. The pyrolysis of the precursor in a dynamic vacuum or ammonia atmosphere at 600C and subsequent sintering of the powder at 900C furnishes crystalline zirconium nitride. Transmission electron microscopy of the powder shows that the particles are coated with a thin zirconium oxide layer. Crystalline zirconium nitride powder, free from zirconium oxide impurities, is obtained if the sintering is carried out at 1075C.