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

0542097 - FZÚ 2022 RIV US eng J - Journal Article
Misra, S. - Barreteau, C. - Crivello, J.C. - Giordano, V.M. - Castellan, J.P. - Sidis, Y. - Levinský, Petr - Hejtmánek, Jiří - Malaman, B. - Dauscher, A. - Lenoir, B. - Candolfi, C. - Pailhes, S.
Reduced phase space of heat-carrying acoustic phonons in single-crystalline InTe.
Physical Review Research. Roč. 2, č. 4 (2020), č. článku 043371. E-ISSN 2643-1564
Institutional support: RVO:68378271
Keywords : thermal-conductivity * thermoelectrics * inelastic neutron scattering * InTe single crystal
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Method of publishing: Open access

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.

Permanent Link: http://hdl.handle.net/11104/0319591