AVS 51st International Symposium
    Materials Solutions for Cooling Technology Topical Conference Monday Sessions
       Session CT+TF-MoM

Invited Paper CT+TF-MoM4
Thermal Transport in Nanostructured Materials

Monday, November 15, 2004, 9:20 am, Room 303B

Session: Thermal Transport in Thin Films and Nanostructured Materials
Presenter: D. Cahill, University of Illinois, Urbana-Champaign
Correspondent: Click to Email
The thermal conductance of interfaces is a key factor in controlling the thermal conductivity of materials with high densities of internal interfaces, e.g., nanocomposites, nanocrystalline ceramics, and short-period multilayer films and superlattices. Low interface conductance puts a lower limit on the size of nanoparticles that can be used as fillers in thermal interface materials and limits the increases in the the thermal conductivity that can be achieved in carbon nanotubes composites. We study these effects using high-precision measurements of thermal conductivity using the 3-omega method and psec transient absorption measurements of the thermal decay time of carbon-nanotubes suspended in micelles in water. We have also recently advanced the state-of-the-art of time-domain-thermoreflectance (TDTR) measurements of thermal transport and are using TDTR to study heat transport across individual interfaces and the thermal conductivity of sputtered multilayers. The thermal conductance of epitaxial interfaces between similar materials approaches the high values predicted by simple theory. Nanolaminates of dissimilar materials show remarkable reductions in thermal conductivity when the layer thickness is a few nm; this approach provides a novel materials with ultra-low thermal conductivity without sacrificing strength or environmental protection.