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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physics Letters A

ISSN

0375-9601

e-ISSN

—

Svazek periodika

382

Číslo periodika v rámci svazku

29

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

5

Strana od-do

1937-1941

Kód UT WoS článku

000435750300007

EID výsledku v databázi Scopus

—