| Abstract Scope |
Zirconium carbide (ZrCx, 0.5≤x≤1) has wide range of substoichiometry facilitated by varying numbers of carbon vacancies. At high temperatures, these vacancies form a continuous solution phase, but at lower temperatures, long- and short-range ordering is predicted and occasionally observed, where vacancies self-assemble into a homologous series of superstructural ordered phases. The thermophysical properties are affected by the number of vacancies and their arrangement, allowing potential application as a tuneable ceramic. The mechanism of vacancy ordering in zirconium carbide is described using insights from first-principles calculations, and possible reasons for the infrequent experimental fabrication of ordered phases are discussed, including fabrication temperatures, vacancy diffusion, and the effects of impurities. |