Cited by 196Thermal properties of materialsAdvanced Thermoelectric Materials and DevicesThermoelastic and Magnetoelastic Phenomena

Determining Phonon Mean Free Paths from Observations of Quasiballistic Thermal Transport

Minnich, A. J.·2012·Physical Review Letters

Abstract

The mean free paths (MFPs) of thermal phonons are mostly unknown in many solids. Recent work indicates that MFPs may be measured using experimental observations of quasiballistic thermal transport, but the precise relationship between the measurements and the MFP distribution remains unclear. Here, we present a method that can accurately reconstruct the MFP distribution from quasiballistic thermal measurements without any assumptions regarding the phonon scattering mechanisms. Our result will enable a substantially improved understanding of thermal transport in many solids, particularly thermoelectrics.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1103/physrevlett.109.205901

Cites

22 of 22 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

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?

  • The measured bulk thermal conductivity is in reasonable agreement with transient grating data for grating period 9.8 μm, indicating that phonon mean free paths are shorter than about 1.5 μm.

    “Second, within the uncertainty of the measurements, the measured bulk thermal conductivity is in reasonable agreement with the TG data for L = 9.8 μm, indicating that the phonon mean free paths are shorter than ∼9.8/2π∼1.5 μm (ref. 64).”

    From Origin of high thermal conductivity in disentangled ultra-high molecular weight polyethylene films: ballistic phonons within enlarged crystals (2022) · cites this paper as [64]

    The discussion of thermal conductivity spectroscopy explains that phonons with mean free paths longer than the thermal length scale have suppressed heat flux, supporting the general inference behind the claim. The application to transient-grating measurements concerns a 390 nm silicon membrane, however; our copy does not report agreement between a measured bulk conductivity and data at a 9.8 μm grating period, or draw the stated 1.5 μm conclusion from that comparison. The indexed passages provide no page numbers. (LLM, conf=0.78)

    Experimental — accuracy not yet measured
  • The derivative of S_r, denoted the kernel, can directly be used to obtain cumulative MFP distribution of an unknown material from experimental measurements of thermal conductivity for different pump sizes with TDTR.

    “The derivative of S r , denoted the kernel, is also shown in Fig. 2(b) and can directly be used to obtain cumulative MFP distribution of an unknown material from experimental measurements of thermal conductivity for different pump sizes with TDTR.19”

    From Radial quasiballistic transport in time-domain thermoreflectance studied using Monte Carlo simulations (2014) · cites this paper as [19]

    The paper defines the kernel as the derivative of a suppression function and describes reconstructing a cumulative MFP distribution from effective thermal conductivities measured over several thermal lengths (main text, Eqs. 2–3 and measurement-procedure discussion; page unavailable). It does not establish the specific TDTR pump-size application or identify the kernel as the derivative of S_r; its demonstrated geometry uses transient-grating wavelengths. Reconstruction also requires solving an inverse problem by convex optimization, rather than using the kernel alone. (LLM, conf=0.87)

    Experimental — accuracy not yet measured
  • The mean free path distribution can be reconstructed from measurements of quasiballistic heat conduction using a method introduced by Minnich, provided that the quasiballistic transport in the experiment can be accurately simulated.

    “The MFP distribution can be reconstructed from these measurements using a method introduced by Minnich provided that the quasiballistic transport in the experiment can be accurately simulated.19”
  • Previously, this equation was used to find the MFP distribution.

    “Previously, this equation was used to find the MFP distribution.19”
  • Minnich recently introduced a framework in which the MFP distribution of the substrate can be reconstructed from effective thermal conductivities and a suppression function that describes the difference in heat flux between quasiballistic and Fourier predictions.

    “Minnich recently introduced a framework in which the MFP distribution of the substrate can be reconstructed from the effective thermal conductivities, as shown in Fig. 2(a)), and a suppression function that describes the difference in heat flux between the quasiballistic and Fourier predictions.19”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. [5]H. Casimir, Physica (Amsterdam) 5 , 495 (1938). http://dx.doi.org/10.1016/S0031-8914(3880162-2) · DOI

Cited by

Sorted by citations

Authors
Minnich, A. J.
Affiliations
California Institute of Technology (US)
Corresponding author
Minnich, A. J.
Venue
Physical Review Letters
Published
2012-11-13
Volume
109
Issue
20
Pages
205901-205901
ISSN
  • 0031-9007 (ISSN-L)
  • 1079-7114
OpenAlex
W2071546751
Cited by
196
References
22
Citations by year
2026: 3 · 2025: 12 · 2024: 15 · 2023: 10 · 2022: 12 · 2021: 16 · 2020: 10 · 2019: 16 · 2018: 14 · 2017: 17 · 2016: 21 · 2015: 25 · 2014: 17 · 2013: 8
FWCI
7.35
Type
journal article
Language
en
Open access
closed
Locations
  • Physical Review Letters (publishedVersion)
  • PubMed (publishedVersion)
  • CaltechAUTHORS (California Institute of Technology) (submittedVersion)
Topics
  • Physical Sciences › Materials Science › Materials Chemistry › Thermal properties of materials
  • Physical Sciences › Materials Science › Materials Chemistry › Advanced Thermoelectric Materials and Devices
  • Physical Sciences › Engineering › Mechanics of Materials › Thermoelastic and Magnetoelastic Phenomena
Keywords
phonon mean free path, thermal conductivity, phonon scattering, thermoelectric materials

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