Retreat from Stress: Rattling in a Planar Coordination

Thermoelectric devices convert heat flow to charge flow, providing electricity. Materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. Thermal conductivity in caged compounds is known to be suppressed by a large vibr...

Full description

Saved in:
Bibliographic Details
Published in:Advanced materials (Weinheim) 2018-03, Vol.30 (13), p.e1706230-n/a
Main Authors: Suekuni, Koichiro, Lee, Chul Ho, Tanaka, Hiromi I., Nishibori, Eiji, Nakamura, Atsushi, Kasai, Hidetaka, Mori, Hitoshi, Usui, Hidetomo, Ochi, Masayuki, Hasegawa, Takumi, Nakamura, Mitsutaka, Ohira‐Kawamura, Seiko, Kikuchi, Tatsuya, Kaneko, Koji, Nishiate, Hirotaka, Hashikuni, Katsuaki, Kosaka, Yasufumi, Kuroki, Kazuhiko, Takabatake, Toshiro
Format: Article
Language:English
Subjects:
Atomic structure
Cage compounds
Charge materials
Copper
Crystal structure
Dynamic structural analysis
Electrical resistivity
Heat conductivity
Heat transfer
Heat transmission
Materials science
Metalloids
neutron scattering
Phonons
rattling
tetrahedrites
Thermal conductivity
Thermoelectric materials
Vibration
X‐ray diffraction
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Thermoelectric devices convert heat flow to charge flow, providing electricity. Materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. Thermal conductivity in caged compounds is known to be suppressed by a large vibration of guest atoms, so‐called rattling, which effectively scatters phonons. Here, the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)12(Sb,As)4S13 are studied. The results reveal that the Cu atoms in a planar coordination are rattling. In contrast to caged compounds, chemical pressure enlarges the amplitude of the rattling vibration in the tetrahedrites so that the rattling atom is squeezed out of the planar coordination. Furthermore, the rattling vibration shakes neighbors through lone pairs of the metalloids, Sb and As, which is responsible for the low thermal conductivity of tetrahedrites. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination. The rattling of Cu atoms in tetrahedrites originates from the chemical pressure inherent in the trigonal‐planar environment. When the chemical pressure is increased with reduction of the S3 triangle area, the rattling amplitude is enlarged. The rattling vibration can shake neighboring metalloid atoms via assistance from the lone pairs of the metalloids.
ISSN:0935-9648
1521-4095
DOI:10.1002/adma.201706230