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Ultralow Lattice Thermal Conductivity at Room Temperature in Cu 4 TiSe 4
Author(s) -
Koley Biplab,
Lakshan Achintya,
Raghuvanshi Parul R.,
Singh Charanpreet,
Bhattacharya Amrita,
Jana Partha P.
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202014222
Subject(s) - thermoelectric materials , thermal conductivity , materials science , phonon , condensed matter physics , thermoelectric effect , electrical resistivity and conductivity , crystal structure , lattice (music) , band gap , chemistry , crystallography , optoelectronics , physics , thermodynamics , composite material , quantum mechanics , acoustics
Ultralow thermal conductivity draws great attention in a variety of fields of applications such as thermoelectrics and thermal barrier coatings. Herein, the crystal structure and transport properties of Cu 4 TiSe 4 are reported. Cu 4 TiSe 4 is a unique example of a non‐toxic and low‐cost material that exhibits a lattice ultra‐low thermal conductivity of 0.19 Wm −1 K −1 at room temperature. The main contribution to the unusually low thermal conductivity is connected with the atomic lattice and its dynamics. This ultralow value of lattice thermal conductivity ( k L ) can be attributed to the presence of the localized modes of Cu, which partially hybridize with the Se atoms, which in turn leads to avoidance of crossing of acoustic phonon modes that reach the zone boundary with a reduced frequency. Like a phonon glass electron crystal, Cu 4 TiSe 4 could also open a route to efficient thermoelectric materials, even, with chalcogenides of relatively high electrical resistivity and a large band gap, provided that their structures offer a sublattice with lightly bound cations.