Quasi-ballistic thermal transport from nanoscale interfaces observed using ultrafast coherent soft x-ray beams
Heat dissipation from a nanoscale hot-spot is expected to be non-diffusive when a hot-spot is smaller than the phonon mean free path of the substrate. Our technique of observing diffraction of coherent soft x-ray pulses allows for very high resolution (∼pm) of thermally-induced surface distortion, a...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Published: |
SPIE
2018
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| Online Access: | http://hdl.handle.net/1721.1/113414 https://orcid.org/0000-0001-7804-5418 |
| Summary: | Heat dissipation from a nanoscale hot-spot is expected to be non-diffusive when a hot-spot is smaller than the phonon mean free path of the substrate. Our technique of observing diffraction of coherent soft x-ray pulses allows for very high resolution (∼pm) of thermally-induced surface distortion, as well as femtosecond time resolution of dynamics. We successfully model our experimental results with a diffusive transport model that is modified to include an additional boundary resistance. These results confirm the importance of considering ballistic transport away from a nanoscale heat source, and identify a means of correctly accounting for this ballistic transport. |
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