Characterization of Thermo-niechanical Properties of Carbon-based Lowdimensional Material/Metallic Thin-film Composites from NEMS Structures.

摘要

Metallic thin-films are widely used in many nano-scale applications- from passive interconnect to active sensors- as they possess good conductivities, both electrical and thermal, and optical reflectivities. To effectively and efficiently apply such material properties at reduced dimension, a better understanding of how such macroscopic properties scale with physical dimension. For example, it is well known when metallic thin-film thickness approach nanoscales (~100nm), their thermal properties are abruptly reduced (1). And, mechanical properties of metallic thin-films make them impractical to realize high-frequency nanomechanical resonator structures. On the other hand carbon-based low-dimensional materials (CBLDMs), such as Graphene and carbon nanotubs (CNTs), are well known for their exceptionally high thermal conductivities and high elastic moduli. So a composite between metallic thin-films and CBLDMs may result in a new generation of nano-materials. Here we report the direct measurement of their thermal properties (such as thermal conductivity) as well as indirect measurement of thermo-elastic properties from resonant response of metallic thin-film/CBLDMs nanomechanical structures.