THIN-FILM MATERIALS AND MINIMUM THERMAL-CONDUCTIVITY

The theoretical minimum thermal conductivity can be used to model heat transport in a wide variety of bulk and thin-film materials with stro ng atomic-scale disorder. To explore the possibility of using metastab le microstructures in thin-film materials to achieve significant reduc tions in conductivity, we present experimental results-obtained using the 3 omega method in the temperature range 77-400 R-on two novel syst ems. (I) The thermal conductivity of a low-dielectric-constant ''flowa ble oxide'' (HSiO1.5, hydrogen silsesquioxane) is greatly reduced rela tive to SiO2. (2) The thermal conductivity of stabilized zirconia /SiO 2 mrdtilayms is unchanged by solid-solid interfaces separated by nanom eter length scales.