Nanoscale thermal radiation between two gold surfaces

In this letter, we measured the nanoscale thermal radiation between a microsphere and a substrate which were both coated with thick gold films. Although gold is highly reflective for thermal radiation, the radiative heat transfer between two gold surfaces was demonstrated to be significantly enhance...

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Bibliographic Details
Main Authors: Shen, Sheng, Mavrokefalos, Anastassios, Sambegoro, Poetro Lebdo, Chen, Gang
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Language:en_US
Published: American Institute of Physics (AIP) 2013
Online Access:http://hdl.handle.net/1721.1/78324
https://orcid.org/0000-0002-9081-2314
https://orcid.org/0000-0002-3968-8530
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Summary:In this letter, we measured the nanoscale thermal radiation between a microsphere and a substrate which were both coated with thick gold films. Although gold is highly reflective for thermal radiation, the radiative heat transfer between two gold surfaces was demonstrated to be significantly enhanced at nanoscale gaps beyond the blackbody radiation limit due to the tunneling of non-resonant evanescent waves. The measured heat transfer coefficient between two gold surfaces agreed well with theoretical prediction. At a gap d = 30 nm ± 5 nm, the heat transfer coefficient between two gold surfaces was observed to be as large as ∼400 W/m[superscript 2]·K, much greater than the blackbody radiation limit (∼5 W/m[superscript 2]·K).