Intrinsic anharmonic localization in thermoelectric PbSe
| Autor: | Hong Wang, Ahmet Alatas, P. Stonaha, Nina Shulumba, Jeffrey W. Lynn, Brian C. Sales, Raphaël P. Hermann, Olle Hellman, Andrew F. May, Vasile O. Garlea, Michael Manley, Austin J. Minnich, John D. Budai |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Materials science Phonon Science Physics::Optics General Physics and Astronomy 02 engineering and technology Neutron scattering General Biochemistry Genetics and Molecular Biology Article Crystal Condensed Matter::Materials Science 03 medical and health sciences Thermal conductivity Condensed Matter::Superconductivity Thermoelectric effect Physics::Chemical Physics lcsh:Science Thermoelectrics Multidisciplinary Condensed matter physics Scattering Anharmonicity General Chemistry Nonlinear phenomena 021001 nanoscience & nanotechnology 030104 developmental biology Group velocity lcsh:Q 0210 nano-technology |
| Zdroj: | Nature Communications Nature Communications, Vol 10, Iss 1, Pp 1-9 (2019) |
| Popis: | Lead chalcogenides have exceptional thermoelectric properties and intriguing anharmonic lattice dynamics underlying their low thermal conductivities. An ideal material for thermoelectric efficiency is the phonon glass–electron crystal, which drives research on strategies to scatter or localize phonons while minimally disrupting electronic-transport. Anharmonicity can potentially do both, even in perfect crystals, and simulations suggest that PbSe is anharmonic enough to support intrinsic localized modes that halt transport. Here, we experimentally observe high-temperature localization in PbSe using neutron scattering but find that localization is not limited to isolated modes – zero group velocity develops for a significant section of the transverse optic phonon on heating above a transition in the anharmonic dynamics. Arrest of the optic phonon propagation coincides with unusual sharpening of the longitudinal acoustic mode due to a loss of phase space for scattering. Our study shows how nonlinear physics beyond conventional anharmonic perturbations can fundamentally alter vibrational transport properties. To optimize the performance of lead chalcogenides for thermoelectric applications, strategies to further reduce the crystal’s thermal conductivity is required. Here, the authors discover anharmonic localized vibrations in PbSe crystals for optimizing the crystal’s vibrational transport properties. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|