Temperature-dependent phonon lifetimes and thermal conductivity of silicon by inelastic neutron scattering and ab initio calculations
| Autor: | Douglas L. Abernathy, J. E. Herriman, Jennifer L. Niedziela, Dennis S. Kim, Chen Li, Olle Hellman, Hillary L. Smith, Nina Shulumba, C. N. Saunders, Brent Fultz, Jiao Y. Y. Lin |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Phonon Ab initio 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Boltzmann equation Inelastic neutron scattering Brillouin zone Condensed Matter::Materials Science Thermal conductivity Ab initio quantum chemistry methods 0103 physical sciences Atom Atomic physics 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review B. 102 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.174311 |
| Popis: | Inelastic neutron scattering on a single crystal of silicon was performed at temperatures from 100 to 1500 K. These experimental data were reduced to obtain phonon spectral intensity at all wave vectors $\stackrel{P\vec}{Q}$ and frequencies $\ensuremath{\omega}$ in the first Brillouin zone. Thermal broadenings of the phonon peaks were obtained by fitting and by calculating with an iterative ab initio method that uses thermal atom displacements on an ensemble of superlattices. Agreement between the calculated and experimental broadenings was good, with possible discrepancies at the highest temperatures. Distributions of phonon widths versus phonon energy had similar shapes for computation and experiment. These distributions grew with temperature but maintained similar shapes. Parameters from the ab initio calculations were used to obtain the thermal conductivity from the Boltzmann transport equation, which was in good agreement with experimental data. Despite the high group velocities of longitudinal acoustic phonons, their shorter lifetimes reduced their contribution to the thermal conductivity, which was dominated by transverse acoustic modes. |
| Databáze: | OpenAIRE |
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