Synthesis and characterisation of novel single-phase HfC_xN_1-x ceramic powders

Hafnium carbonitride (HfC_xN_1-x) powders were successfully synthesised from a mixture of Hf, C, and HfN powders using the solid-reaction method at 2400 °C for 30 min in a nitrogen atmosphere. The basic properties of the as-prepared HfC_xN_1-x powders, including the particle size, phase composition, microstructure, morphology, chemical bond composition and crystal structure were analysed using X-Ray diffraction, scanning electron microscopy, X-Ray photoelectron spectroscopy, and transmission electron microscopy. The as-prepared HfC_xN_1-x powders had a singlecrystalline structure of metal carbonitride and simultaneously possessed high purity. The mean particle size of the as-prepared HfC_xN_1-x powders was approximately 2 μm, and the chemical composition ratios of Hf, C, and N in the as-prepared powder samples were close to the stoichiometric values. These elements were evenly distributed in the powder samples. The results confirmed that the powders consisted of Hf–C and Hf–N bonds with a Hf/(C + N) ratio of approximately 1. The HfC_xN_1-x (x = 0.7, 0.6, 0.5, 0.4, 0.3) powders had a cubic crystal structures.