Reconstruction of the phonon relaxation times using solutions of the Boltzmann transport equation
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Mechanical Engineering
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
We present a method for reconstructing the phonon relaxation time distribution τω = τ ( ω ) (including polarization) in a material from thermal spectroscopy data. The distinguishing feature of this approach is that it does not make use of the effective thermal conductivity concept and associated approximations. The reconstruction is posed as an optimization problem in which the relaxation times τω = τ (ω) are determined by minimizing the discrepancy between the experimental relaxation traces and solutions of the Boltzmann transport equation for the same problem. The latter may be analytical, in which case the procedure is very efficient, or numerical. The proposed method is illustrated using Monte Carlo solutions of thermal grating relaxation as synthetic experimental data. Lastly, the reconstruction is shown to agree very well with the relaxation times used to generate the synthetic Monte Carlo data and remains robust in the presence of uncertainty (noise).
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Solid-State Solar-Thermal Energy Conversion Center (S3TEC); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0001299; FG02-09ER46577
- OSTI ID:
- 1388455
- Alternate ID(s):
- OSTI ID: 1329948
- Journal Information:
- Physical Review B, Vol. 94, Issue 15; Related Information: S3TEC partners with Massachusetts Institute of Technology (lead); Boston College; Oak Ridge National Laboratory; Rensselaer Polytechnic Institute; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
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journal | January 2019 |
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