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 degrees 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.