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 inter-facial 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 inter-facial thermal resistance and reduced dimensionality or grain size, rather than by focusing on minimization of bulk thermal conductivity alone. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.