Cited by 61Thermal properties of materialsThermoelastic and Magnetoelastic PhenomenaThermography and Photoacoustic Techniques

Nonlocal theory for heat transport at high frequencies

Koh, Yee Kan, Cahill, David G., Sun, Bo·2014·Physical Review B

Abstract

We develop a nonlocal theory for heat conduction under high-frequency temperature fields and apply the theory to explain reductions of the apparent thermal conductivity observed in recent experiments. Our nonlocal theory is an analytical solution of the Boltzmann transport equation for phonons in a semi-infinite solid, similar to a prior nonlocal theory for heat conduction under a high-temperature gradient but subjected to periodic heating at the surface. The boundary condition of periodic heating, as opposed to prior calculations of heating by a single laser pulse, better mimics time-domain thermoreflectance (TDTR) and broadband frequency-domain thermoreflectance (BB-FDTR) measurements. We find that, except for pure crystals at high frequencies, the effective thermal conductivity derived using the nonlocal theory compares well with calculations of a modified Callaway model that includes an upper limit on the phonon mean-free path at twice the thermal penetration depth. For pure crystals, however, the effective thermal conductivity derived from the out-of-phase calculations are independent of frequency, in agreement with prior TDTR measurements, due to the countereffect of reduced heat flux and diminished relative phase between the heat flux and temperature oscillations at high frequencies. Our results suggest that empirical interpretation of ballistic phonons not contributing to heat conduction is not general and can only be applied to measurements on alloys and not pure crystals, even when a large laser spot size is used in the experiments and the interfacial thermal resistance is negligible.

Integrity signals

Registry

Crossref · 10.1103/physrevb.90.205412

Cites

32 of 32 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Koh and Cahill were the first to observe a modulation-frequency-dependent thermal conductivity in some semiconductor alloys measured using TDTR, and they attributed it to the non-diffusive phonon transport.

    “Koh and Cahill 90 were the first to observe a modulation-frequency-dependent thermal conductivity in some semiconductor alloys measured using TDTR, and they attributed it to the non-diffusive phonon transport, i.e. , phonons with Λ ൐ ݀ ௣ (and Λ ൐ 2 ݀ ௣ in their later publication 209 ) do not contribute to the apparent thermal conductivity measured by TDTR.”
  • The simple interpretation that phonons with Λ > dp do not contribute to the apparent thermal conductivity works as a good approximation only for semiconductor alloys due to their extremely broad MFP distributions but not for pure crystals.

    “This simple interpretation, however, works as a good approximation only for semiconductor alloys due to their extremely broad MFP distributions 209 but not for pure crystals, as frequency dependence was not observed in TDTR measurements of crystalline Si despite its very long MFPs of phonons 185, 187 .”

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Koh, Y. K., Cahill, D. G., & Sun, B.
Affiliations
  • University of Illinois Urbana-Champaign (US)
  • National University of Singapore (SG)
Venue
Physical Review B
Published
2014-11-11
Volume
90
Issue
20
ISSN
  • 1098-0121 (ISSN-L)
  • 1550-235X
OpenAlex
W2315339812
Cited by
60
References
32
Citations by year
2026: 1 · 2025: 8 · 2024: 4 · 2023: 2 · 2022: 3 · 2021: 2 · 2020: 5 · 2019: 8 · 2018: 8 · 2017: 8 · 2016: 7 · 2015: 4
FWCI
2.88
Type
journal article
Language
en
Open access
closed
Locations
Physical Review B (publishedVersion)
Funders
Ministry of Education - Singapore (MOE2013-T2-2-147)
Topics
  • Physical Sciences › Materials Science › Materials Chemistry › Thermal properties of materials
  • Physical Sciences › Engineering › Mechanics of Materials › Thermoelastic and Magnetoelastic Phenomena
  • Physical Sciences › Engineering › Mechanics of Materials › Thermography and Photoacoustic Techniques
Keywords
nonlocal heat conduction, phonon Boltzmann transport equation, effective thermal conductivity, time-domain thermoreflectance, Callaway model, phonon mean free path, ballistic phonons, pure crystals, alloys, thermal penetration depth

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review