Thermal Conductivity Spectroscopy Technique to Measure Phonon Mean Free Paths

Size effects in heat conduction, which occur when phonon mean free paths (MFPs) are comparable to characteristic lengths, are being extensively explored in many nanoscale systems for energy applications. Knowledge of MFPs is essential to understanding size effects, yet MFPs are largely unknown for m...

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Bibliographic Details
Main Authors: Schmidt, A. J., Minnich, Austin Jerome, Johnson, Jeremiah A., Esfarjani, Keivan, Dresselhaus, Mildred, Nelson, Keith Adam, Chen, Gang
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: American Physical Society (APS) 2012
Online Access:http://hdl.handle.net/1721.1/68676
https://orcid.org/0000-0001-8492-2261
https://orcid.org/0000-0002-3968-8530
https://orcid.org/0000-0001-7804-5418
https://orcid.org/0000-0001-9157-6491
Description
Summary:Size effects in heat conduction, which occur when phonon mean free paths (MFPs) are comparable to characteristic lengths, are being extensively explored in many nanoscale systems for energy applications. Knowledge of MFPs is essential to understanding size effects, yet MFPs are largely unknown for most materials. Here, we introduce the first experimental technique which can measure MFP distributions over a wide range of length scales and materials. Using this technique, we measure the MFP distribution of silicon for the first time and obtain good agreement with first-principles calculations.