TY - JOUR

T1 - Microscopic mechanism of unusual lattice thermal transport in TlInTe2

AU - Pal, Koushik

AU - Xia, Yi

AU - Wolverton, Chris

N1 - Funding Information:
We acknowledge financial supports from the Department of Energy, Office of Science, Basic Energy Sciences under grant DE-SC0014520 and the U.S. Department of Commerce and National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD) under award no. 70NANB14H012 (DFT calculations). One of us (Y.X.) is partially supported by the Toyota Research Institute (TRI) through the Accelerated Materials Design and Discovery program (theory of anharmonic phonons). K.P. thanks Shashwat Anand for constructive comments on the manuscript. This work used computing resources provided by the (a) National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy office of Science User Facility operated under Contract No. DE-AC02-05CH11231, (b) the Extreme Science and Engineering Discovery Environment (National Science Foundation Contract ACI-1548562), and (c) Quest high-performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology.
Publisher Copyright:
© 2021, The Author(s).

PY - 2021/12

Y1 - 2021/12

N2 - We investigate the microscopic mechanism of ultralow lattice thermal conductivity (κl) of TlInTe2 and its weak temperature dependence using a unified theory of lattice heat transport, that considers contributions arising from the particle-like propagation as well as wave-like tunneling of phonons. While we use the Peierls–Boltzmann transport equation (PBTE) to calculate the particle-like contributions (κl(PBTE)), we explicitly calculate the off-diagonal (OD) components of the heat-flux operator within a first-principles density functional theory framework to determine the contributions (κl(OD)) arising from the wave-like tunneling of phonons. At each temperature, T, we anharmonically renormalize the phonon frequencies using the self-consistent phonon theory including quartic anharmonicity, and utilize them to calculate κl(PBTE) and κl(OD). With the combined inclusion of κl(PBTE), κl(OD), and additional grain-boundary scatterings, our calculations successfully reproduce the experimental results. Our analysis shows that large quartic anharmonicity of TlInTe2 (a) strongly hardens the low-energy phonon branches, (b) diminishes the three-phonon scattering processes at finite T, and (c) recovers the weaker than T−1 decay of the measured κl.

AB - We investigate the microscopic mechanism of ultralow lattice thermal conductivity (κl) of TlInTe2 and its weak temperature dependence using a unified theory of lattice heat transport, that considers contributions arising from the particle-like propagation as well as wave-like tunneling of phonons. While we use the Peierls–Boltzmann transport equation (PBTE) to calculate the particle-like contributions (κl(PBTE)), we explicitly calculate the off-diagonal (OD) components of the heat-flux operator within a first-principles density functional theory framework to determine the contributions (κl(OD)) arising from the wave-like tunneling of phonons. At each temperature, T, we anharmonically renormalize the phonon frequencies using the self-consistent phonon theory including quartic anharmonicity, and utilize them to calculate κl(PBTE) and κl(OD). With the combined inclusion of κl(PBTE), κl(OD), and additional grain-boundary scatterings, our calculations successfully reproduce the experimental results. Our analysis shows that large quartic anharmonicity of TlInTe2 (a) strongly hardens the low-energy phonon branches, (b) diminishes the three-phonon scattering processes at finite T, and (c) recovers the weaker than T−1 decay of the measured κl.

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U2 - 10.1038/s41524-020-00474-5

DO - 10.1038/s41524-020-00474-5

M3 - Article

AN - SCOPUS:85098733329

VL - 7

JO - npj Computational Materials

JF - npj Computational Materials

SN - 2057-3960

IS - 1

M1 - 5

ER -