Ultralow Lattice Thermal Conductivity in Complex Structure Cu26V2Sn6Se32 due to Interaction of Low-Frequency Acoustic-Optical Phonons

Fuente: arXiv
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Autores principales: Rana, Kewal Singh, Sarkar, Debattam, Nidhi, Singh, Aditya, Bera, Chandan, Biswas, Kanishka, Soni, Ajay
Formato: Preprint
Publicado: 2024
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author Rana, Kewal Singh
Sarkar, Debattam
Nidhi
Singh, Aditya
Bera, Chandan
Biswas, Kanishka
Soni, Ajay
author_facet Rana, Kewal Singh
Sarkar, Debattam
Nidhi
Singh, Aditya
Bera, Chandan
Biswas, Kanishka
Soni, Ajay
contents Damping of phonon momentum suppresses the lattice thermal conductivity (kl) through low energy acoustic-optical phonon interactions. We studied the thermal transport properties and underlying mechanism of phonon interactions in the large unit cell Cu26V2Sn6Se32. The large number of atoms in the unit cell results in low acoustic phonon cutoff frequency, flat phonon branches, low frequency Raman active modes, localized rattler-like vibrations and strong crystalline anharmonicity. The crystal structure complexity disrupts the phonon propagation through weak bonded Cu atoms, boson peak and poor phonon velocity. The sulfur at selenium sites (Cu26V2Sn6Se30S2) distort the crystal lattice by offering additional scattering mechanism at the anionic sites, thereby increases the power factor and decreases the kl. This strategic manipulation of phonon scattering towards ultra-low kl not only results in improved thermoelectric performance but also offers insights into the fundamental understanding of heat transport in complex structured, large unit cell compounds.
format Preprint
id arxiv_https___arxiv_org_abs_2401_03517
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ultralow Lattice Thermal Conductivity in Complex Structure Cu26V2Sn6Se32 due to Interaction of Low-Frequency Acoustic-Optical Phonons
Rana, Kewal Singh
Sarkar, Debattam
Nidhi
Singh, Aditya
Bera, Chandan
Biswas, Kanishka
Soni, Ajay
Materials Science
Damping of phonon momentum suppresses the lattice thermal conductivity (kl) through low energy acoustic-optical phonon interactions. We studied the thermal transport properties and underlying mechanism of phonon interactions in the large unit cell Cu26V2Sn6Se32. The large number of atoms in the unit cell results in low acoustic phonon cutoff frequency, flat phonon branches, low frequency Raman active modes, localized rattler-like vibrations and strong crystalline anharmonicity. The crystal structure complexity disrupts the phonon propagation through weak bonded Cu atoms, boson peak and poor phonon velocity. The sulfur at selenium sites (Cu26V2Sn6Se30S2) distort the crystal lattice by offering additional scattering mechanism at the anionic sites, thereby increases the power factor and decreases the kl. This strategic manipulation of phonon scattering towards ultra-low kl not only results in improved thermoelectric performance but also offers insights into the fundamental understanding of heat transport in complex structured, large unit cell compounds.
title Ultralow Lattice Thermal Conductivity in Complex Structure Cu26V2Sn6Se32 due to Interaction of Low-Frequency Acoustic-Optical Phonons
topic Materials Science
url https://arxiv.org/abs/2401.03517