The Library
Super-suppression of long phonon mean-free-paths in nano-engineered Si due to heat current anticorrelations
Tools
Tools
Tools
Hosseini, S. Aria, Davies, Alathea, Dickey, Ian, Neophytou, Neophytos, Greaney, P. Alex and de Sousa Oliveira, Laura (2022) Super-suppression of long phonon mean-free-paths in nano-engineered Si due to heat current anticorrelations. Materials Today Physics, 27 . 100719. doi:10.1016/j.mtphys.2022.100719 ISSN 2542-5293.
![[img]](http://wrap.warwick.ac.uk/style/images/fileicons/application_pdf.png) |
PDF
WRAP-Super-suppression-long-phonon-nano-engineered-Si-heat-anticorrelations-22.pdf - Accepted Version Embargoed item. Restricted access to Repository staff only until 20 June 2023. Contact author directly, specifying your specific needs. - Requires a PDF viewer. Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (10Mb) |
Official URL: https://doi.org/10.1016/j.mtphys.2022.100719
Abstract
The ability to minimize the thermal conductivity of dielectrics with minimal structural intervention that could affect electrical properties is an important capability for engineering thermoelectric efficiency in low-cost materials such as Si. We recently reported the discovery of special arrangements for nanoscale pores in Si that produce a particularly large reduction in thermal conductivity accompanied by strongly anticorrelated heat current fluctuations [1] – a phenomenon that is missed by the diffuse adiabatic boundary conditions conventionally used in Boltzmann transport models. This manuscript presents the results of molecular dynamics simulations and a Monte Carlo ray tracing model that teases apart this phenomenon to reveal that special pore layouts elastically backscatter long-wavelength heat-carrying phonons. This means that heat carriage by a phonon before scattering is undone by the scattered phonon, resulting in an effective mean-free-path that is significantly shorter than the geometric line-of-sight due to the pores. This effect is particularly noticeable for the long-wavelength, long mean-free-path phonons whose transport is impeded drastically more than is expected purely from the usual considerations of scattering defined by the distance between defects. This “super-suppression” of the mean-free-path below the characteristic length scale of the nanostructuring offers a route for minimizing thermal conductivity with minimal structural impact, while the stronger impact on long wavelengths offers possibilities for the design of band-pass phonon filtering. Moreover, the ray tracing model developed in this paper shows that different forms of correlated scattering imprint a unique signature in the heat current autocorrelation function that could be used as a diagnostic in other nanostructured systems.
| Item Type: | Journal Article | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Divisions: | Faculty of Science, Engineering and Medicine > Engineering > Engineering | ||||||||
| SWORD Depositor: | Library Publications Router | ||||||||
| Journal or Publication Title: | Materials Today Physics | ||||||||
| Publisher: | Elsevier | ||||||||
| ISSN: | 2542-5293 | ||||||||
| Official Date: | October 2022 | ||||||||
| Dates: |
|
||||||||
| Volume: | 27 | ||||||||
| Article Number: | 100719 | ||||||||
| DOI: | 10.1016/j.mtphys.2022.100719 | ||||||||
| Status: | Peer Reviewed | ||||||||
| Publication Status: | Published | ||||||||
| Access rights to Published version: | Restricted or Subscription Access | ||||||||
| Date of first compliant deposit: | 11 August 2022 |
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
