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Reduced phase space of heat-carrying acoustic phonons in single-crystalline InTe

Misra, Shantanu; Barreteau, Céline; Crivello, Jean-Claude; Giordano, Valentina M.; Castellan, John-Paul; Sidis, Yvan; Levinský, Petr; Hejtmánek, Jiří; Malaman, Bernard; Dauscher, Anne; Lenoir, Bertrand; Candolfi, Christophe; Pailhès, Stéphane

Abstract (englisch):

Chalcogenide semiconductors and semimetals are a fertile class of efficient thermoelectric materials, which, in most cases, exhibit very low lattice thermal conductivity κph despite lacking a complex crystal structure such as the tetragonal binary compound InTe. Our measurements of κph(T) in single-crystalline InTe along the c axis show that κph exhibits a smooth temperature dependence upon cooling to about 50 K, the temperature below which a strong rise typical for dielectric compounds is observed. Using a combination of first-principles calculations, inelastic neutron scattering (INS), and low-temperature specific heat and transport properties measurements on single-crystalline InTe, we show that the phonon spectrum exhibits well-defined acoustic modes, the energy dispersions of which are constrained to low energies due to distributions of dispersionless, optical modes, which are responsible for a broad double peak structure in the low-temperature specific heat. The latter are assigned to the dynamics of In+ cations in tunnels formed by edge-sharing (In3+Te42−)− tetrahedra chains, the atomic thermal displacement parameters of which, probed as a function of temperature by means of single-crystal x-ray diffraction, suggest the existence of a complex energy potential. ... mehr

Verlagsausgabe §
DOI: 10.5445/IR/1000137676
Veröffentlicht am 21.09.2021
DOI: 10.1103/PhysRevResearch.2.043371
Zitationen: 11
Zitationen: 13
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Quantenmaterialien und -technologien (IQMT)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 01.2021
Sprache Englisch
Identifikator ISSN: 2643-1564
KITopen-ID: 1000137676
HGF-Programm 43.21.01 (POF III, LK 01) Quantum Correlations in Condensed Matter
Weitere HGF-Programme 47.11.02 (POF IV, LK 01) Emergent Quantum Phenomena
Erschienen in Physical review research
Verlag American Physical Society (APS)
Band 2
Heft 4
Seiten Article no: 043371
Vorab online veröffentlicht am 14.12.2020
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