Effects of Aperiodicity and Roughness on Coherent Heat Conduction in Superlattices
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Effects of aperiodicity.pdf
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379.21 KB
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Author(s)
Qiu, Bo
Chen, Gang
Tian, Zhiting
Date Issued
October 2015
Journal
Nanoscale and Microscale Thermophysical Engineering
Publisher
Taylor & Francis
Citation
Qiu, Bo, Gang Chen, and Zhiting Tian. “Effects of Aperiodicity and Roughness on Coherent Heat Conduction in Superlattices.” Nanoscale and Microscale Thermophysical Engineering 19, no. 4 (October 2, 2015): 272–278.
Version
Author's final manuscript
Abstract
Coherent phonon heat conduction has recently been confirmed experimentally in superlattice structures. Such traveling coherent phonon waves in superlattices lead to a linear increase in thermal conductivity as the number of periods increases. For applications such as thermal insulation or thermoelectrics, minimization of the phonon coherent effect is desirable. In this work, we use molecular dynamics simulations to study how to control coherent heat conduction in superlattices (SLs). It is found that either aperiodic SLs or SLs with rough interfaces can significantly disrupt coherent heat conduction when the interface densities are high. For sample thickness less than 125 nm, aperiodic SLs with perfect interfaces are found to have the lowest thermal conductivity. We use the atomic Green’s function method to examine the phonon dynamics. The impact of either aperiodicity or interface roughness is attributed to reduced transmittance. Such impact diminishes as the interface density reduces.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1080/15567265.2015.1102186
