Investigation on transport properties and anomalously heat-carrying optical phonons in KXY (X = Ca, Mg; Y = Sb, Bi)
•The effects of phonon renormalization induced by the fourth-order anharmonicity and 4-phonon scattering are fully considered when calculating the KXY thermal transport properties.•We verified the microscopic origin of heat transport from the microscopic point of view of the bonding strength between...
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Veröffentlicht in: | International journal of heat and mass transfer 2023-08, Vol.209, p.124132, Article 124132 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | •The effects of phonon renormalization induced by the fourth-order anharmonicity and 4-phonon scattering are fully considered when calculating the KXY thermal transport properties.•We verified the microscopic origin of heat transport from the microscopic point of view of the bonding strength between atoms and combined with the results of phonon group velocity, scattering rate, Grüneisen parameter, and mean free path.•We capture heat-carrying high-frequency optical phonons that make an anomalous contribution to heat transport.•We verified and predicted the mechanical properties of KXY.
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In this work, we systematically studied the thermal transport properties of ternary zintl compound KXY using self-consistent phonon theory combined with compressive sensing technology and the Boltzmann transport equation. The effects of quartic anharmonic induced phonon renormalization and 4 - phonon scattering on the results are fully considered. Vibrational mode visualization reveals that the anomalous contribution of optical phonons to lattice thermal conductivity in KCaBi originates from high-speed out-of-phase vibrations of Ca atoms. We analyzed the microscopic mechanism of heat transport from the perspective of atomic bonding combined with the results of group velocity, scattering rate, Gru¨neisen parameter, mean free path, etc. In addition, we verified and predicted the mechanical properties in KXY by calculation. |
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ISSN: | 0017-9310 1879-2189 |
DOI: | 10.1016/j.ijheatmasstransfer.2023.124132 |