Abstract
It is widely accepted that the lattice thermal conductivity of a polycrystal mainly depends on its grain sizes, phonon mean free paths, and grain-boundary thermal resistance. However, uncertainties always exist on how much grain misalignment and a wide grain size distribution in a real polycrystal could affect the thermal analysis. Considering frequency-dependent phonon mean free paths, the influence of these factors is carefully examined by phonon Monte Carlo simulations for a series of disordered silicon polycrystals with grain sizes ranging from 1 to 400 nm. More generally, simulations are also performed on thermally anisotropic polycrystals. Despite all structure variation, this work suggests that the direction-averaged lattice thermal conductivity of a polycrystal is always close to that of an aligned polycrystal, with an effective grain size matching the interface density of the studied polycrystal.
| Original language | English (US) |
|---|---|
| Article number | 014309 |
| Journal | Journal of Applied Physics |
| Volume | 111 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2012 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Influence of structure disorder on the lattice thermal conductivity of polycrystals : A frequency-dependent phonon-transport study. / Hao, Qing.
In: Journal of Applied Physics, Vol. 111, No. 1, 014309, 01.01.2012.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Influence of structure disorder on the lattice thermal conductivity of polycrystals
T2 - A frequency-dependent phonon-transport study
AU - Hao, Qing
PY - 2012/1/1
Y1 - 2012/1/1
N2 - It is widely accepted that the lattice thermal conductivity of a polycrystal mainly depends on its grain sizes, phonon mean free paths, and grain-boundary thermal resistance. However, uncertainties always exist on how much grain misalignment and a wide grain size distribution in a real polycrystal could affect the thermal analysis. Considering frequency-dependent phonon mean free paths, the influence of these factors is carefully examined by phonon Monte Carlo simulations for a series of disordered silicon polycrystals with grain sizes ranging from 1 to 400 nm. More generally, simulations are also performed on thermally anisotropic polycrystals. Despite all structure variation, this work suggests that the direction-averaged lattice thermal conductivity of a polycrystal is always close to that of an aligned polycrystal, with an effective grain size matching the interface density of the studied polycrystal.
AB - It is widely accepted that the lattice thermal conductivity of a polycrystal mainly depends on its grain sizes, phonon mean free paths, and grain-boundary thermal resistance. However, uncertainties always exist on how much grain misalignment and a wide grain size distribution in a real polycrystal could affect the thermal analysis. Considering frequency-dependent phonon mean free paths, the influence of these factors is carefully examined by phonon Monte Carlo simulations for a series of disordered silicon polycrystals with grain sizes ranging from 1 to 400 nm. More generally, simulations are also performed on thermally anisotropic polycrystals. Despite all structure variation, this work suggests that the direction-averaged lattice thermal conductivity of a polycrystal is always close to that of an aligned polycrystal, with an effective grain size matching the interface density of the studied polycrystal.
UR - http://www.scopus.com/inward/record.url?scp=84855918749&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84855918749&partnerID=8YFLogxK
U2 - 10.1063/1.3675466
DO - 10.1063/1.3675466
M3 - Article
AN - SCOPUS:84855918749
VL - 111
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 1
M1 - 014309
ER -