A five-component entropy-stabilized fluorite oxide

In this paper, we report a new entropy-stabilized fluorite oxide, formed by solid-state reacting the equimolar mixture of CeO2, ZrO2, HfO2, TiO2 and SnO2 at 1500 °C. We demonstrated that the oxide is truly entropy-stabilized by showing that the oxide was transferred to a multiphase state when annealed at lower temperatures, and the transition between the low-temperature multiphase and high-temperature single-phase states is reversible. Room-temperature thermal conductivity of the fluorite oxide was measured to be 1.28 Wm−1 K−1. The value is only half of that for 7 wt% yttria-stabilized zirconia, suggesting the material could be useful for thermal-insulation applications.