Soft-phonon dynamics of the thermoelectric beta-SnSe at high temperatures

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F18%3A10241934" target="_blank" >RIV/61989100:27740/18:10241934 - isvavai.cz</a>
Result on the web
<a href="https://www.sciencedirect.com/science/article/abs/pii/S0375960118305115" target="_blank" >https://www.sciencedirect.com/science/article/abs/pii/S0375960118305115</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.physleta.2018.05.011" target="_blank" >10.1016/j.physleta.2018.05.011</a>

Result language
angličtina
Original language name
Soft-phonon dynamics of the thermoelectric beta-SnSe at high temperatures
Original language description
Results of inelastic neutron scattering experiments on SnSe single crystals at high temperatures along with theoretical studies based on the density functional theory are reported. Our experiments reveal significant softening of the transverse acoustic branch along the [0, xi, 0] direction in the low-temperature alpha-SnSe of Pbnm symmetry as temperature approaches T-c = 807 K from below. This process is followed by a condensation of the zone-boundary Y-phonon of the high-temperature beta-SnSe with Cmcm symmetry at the onset of phase transition. The employed theoretical approach supports experimental observations and demonstrates that the phase change in SnSe is mediated by an unstable zone-boundary phonon with the Y-2(+) irreducible representation within the Cmcm symmetry space group of the high-temperature beta-SnSe. The present work provides a detailed understanding of the soft-mode dynamics in SnSe and conclusively shows that the alpha reversible arrow beta structural transformation in this currently topical thermoelectric material is of displacive type.
Czech name
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Czech description
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Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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