Unifying first-principles theoretical predictions and experimental measurements of size effects in thermal transport in SiGe alloys
Author(s)
Huberman, Samuel C.
Chiloyan, Vazrik
Duncan, Ryan Andrew
Zeng, Lingping
Jia, Roger Qingfeng
Maznev, Alexei
Fitzgerald, Eugene A
Nelson, Keith Adam
Chen, Gang
Date Issued
October 2017
Journal
Physical Review Materials
Publisher
American Physical Society
Citation
Huberman, Samuel et al. “Unifying First-Principles Theoretical Predictions and Experimental Measurements of Size Effects in Thermal Transport in SiGe Alloys.” Physical Review Materials 1, 5 (October 2017): 054601 © 2017 American Physical Society
Version
Original manuscript
Abstract
We demonstrate the agreement between first-principles calculations and experimental measurements of size effects in thermal transport in SiGe alloys without fitting parameters. Transient thermal grating (TTG) is used to measure the effect of the grating period on the temperature decay. The virtual crystal approximation under the density-functional-theory framework combined with impurity scattering is used to determine the phonon properties for the exact alloy composition of the measured samples. With these properties, classical size effects are calculated for the experimental geometry of reflection mode TTG using the recently developed variational solution to the phonon Boltzmann transport equation, which is verified against established Monte Carlo simulations. We find agreement between theoretical predictions and experimental measurements in the reduction of thermal conductivity (as much as fourfold of the bulk value) across grating periods spanning one order of magnitude. This paper provides a framework for the study of size effects in thermal transport in opaque materials.
MIT Department
Massachusetts Institute of Technology. Center for Materials Science and Engineering
Massachusetts Institute of Technology. Department of Chemistry
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevMaterials.1.054601
