Zirconium oxycarbides and oxycarbonitrides: A review

Abstract

Zirconium oxycarbides and zirconium oxycarbonitrides are high-temperature ceramic materials with great potential for applications in advanced technologies due to their good refractoriness, mechanical and thermoelectric properties, and corrosion resistance. The properties of ZrCO(N) materials strongly depend on their composition. However, the stoichiometry of stable ZrCO(N) compounds, synthesis chemistry, and thermodynamics of the proceeding reactions require clarification. This review comprehensively interprets data for ZrCO and ZrCON ceramics, including studies that may not have been addressed in prior reviews. It summarizes the state-of-the-art synthesis procedures involving reactions between commonly used zirconia, zirconium carbide, and carbon black, along with other zirconium sources widely used in the last few decades for the preparation of ZrCO(N) materials. The controversial reaction mechanisms of carbothermal reduction of zirconia and the role of CO gas in this process are discussed. The properties of ZrCO and ZrCON and their possible applications are also summarized.

A facile route for the synthesis of high‐entropy transition carbides/borides at low temperatures

“…The results show that the values derived from Rietveld refinement are lower than that calculated by the rule of mixtures (“average” value from individual components). The insertions of partial O atoms result in the reduction of lattice constant because of a shorter bond length of Me‐O than Me‐C 44 …”