Journal
NATURE MATERIALS
Volume 9, Issue 1, Pages 26-30Publisher
NATURE PUBLISHING GROUP
DOI: 10.1038/NMAT2568
Keywords
-
Categories
Funding
- DOE Division of Chemical Sciences, Geosciences, and Biosciences
- National Science Foundation Engineering Research Center for Extreme Ultraviolet Science and Technology
- NSF/CAREER [0846561]
- AFOSR/DCT [FA9550-08-1-0078]
Ask authors/readers for more resources
Fourier theory of thermal transport considers heat transport as a diffusive process where energy flow is driven by a temperature gradient. However, this is not valid at length scales smaller than the mean free path for the energy carriers in a material, which can be hundreds of nanometres in crystalline materials at room temperature. In this case, heat flow will become 'ballistic'-driven by direct point-to-point transport of energy quanta(1). Past experiments have demonstrated size-dependent ballistic thermal transport through nanostructures such as thin films, superlattices, nanowires and carbon nanotubes(1-8). The Fourier law should also break down in the case of heat dissipation from a nanoscale heat source into the bulk. However, despite considerable theoretical discussion and direct application to thermal management in nanoelectronics(2), nano-enabled energy systems(9,10) and nanomedicine(11), this non-Fourier heat dissipation has not been experimentally observed so far. Here, we report the first observation and quantitative measurements of this transition from diffusive to ballistic thermal transport from a nanoscale hotspot, finding a significant (as much as three times) decrease in energy transport away from the nanoscale heat source compared with Fourier-law predictions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available