Interfacial thermal resistance in nanocrystalline yttria-stabilized zirconia

The grain-size dependent thermal conductivity of nanocrystalline yttria-stabilized zirconia from 6–480K is reported. The thermal conductivity for a grain size of 10 nm is reduced to approximately half that of coarse-grained or single-crystal material at all measured temperatures. A method for determining the interfacial resistance to thermal transport in polycrystalline materials from measurements of grain-size-dependent thermal conductivity is described and applied. The results suggest a new strategy for identifying improved thermal barrier materials by choosing materials with large interfacial thermal resistance and reduced dimensionality or grain size, rather than by focusing on minimization of bulk thermal conductivity alone.