Ultra-Low Thermal Conductivity in W/Al^sub 2^O^sub 3^ Nanolaminates

Atomic layer deposition and magnetron sputter deposition were used to synthesize thin-film multilayers of W/Al^sub 2^O^sub 3^. With individual layers only a few nanometers thick, the high interface density produced a strong impediment to heat transfer, giving rise to a thermal conductivity of ~0.6 watts per meter per kelvin. This result suggests that high densities of iterfaces between dissimilar materials my provide a route for the production of thermal barriers with ultra-low thermal conductivity. [PUBLICATION ABSTRACT]