Facile and economical routes toward novel high-entropy metal nitride high-temperature ceramic nanograin powders

A facile modified soft-urea route is employed for the direct synthesis of high-entropy metal nitride powders. Low-cost metal chlorides and urea are mixed without organic solvent, and the mixture is thermally treated under N-2 flow. Both ternary (Hf0.5Ta0.5)N and the five metal high-entropy (Hf0.2Ta0.2Zr0.2Nb0.2V0.2)N synthesized are single-phase solid-solution fine powders. The study provides an effective method for synthesis of multi-component, including high-entropy, metal nitride powders. Further investigation is needed to improve the control of materials' exact stoichiometry, phase, and microstructure and reveal the new materials' chemical/physical properties for various potential applications such as energy and catalysis.