Preparation and Characterization of UltraHigh‐Temperature Ternary Ceramics Ta4HfC5

Tantalum hafnium carbide (Ta₄HfC₅) powders were synthesized by solvothermal treatment and carbothermal reduction reactions from an inorganic hybrid. Tantalum pentachloride, hafnium chloride, and phenolic resin were used as the sources of tantalum, hafnium, and carbon, respectively. Pyrolysis of the complexes at 1000°C/1 h initiated the carbothermal reduction to result in multiplex phases including tantalum carbide and hafnium oxide which after heat treatment at 1400°C–1600°C transformed to single‐phase solid solution Ta₄HfC₅ by solid solution reaction. The mean crystallite size of Ta₄HfC₅ particles was less than 80 nm, and the composition of Ta, Hf, and C elements was near stoichiometric and homogeneously distributed in the powder samples. XRD pattern for Ta₄HfC₅ powders was analyzed.