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Title: Enhanced thermoelectric performance of heavy-fermion compounds Yb TM 2 Zn 20 ( TM = Co, Rh, Ir) at low temperatures
Abstract: Thermoelectricity allows direct conversion between heat and electricity, providing alternatives for green energy technologies. Despite these advantages, for most materials the energy conversion efficiency is limited by the tendency for the electrical and thermal conductivity to be proportional to each other and the Seebeck coefficient to be small. Here we report counter examples, where the heavy fermion compounds Yb TM 2 Zn 20 ( TM = Co, Rh, Ir) exhibit enhanced thermoelectric performance including a large power factor ( PF = 74 μW/cm-K 2 ; TM = Ir) and a high figure of merit ( ZT = 0.07; TM = Ir) at 35 K. The combination of the strongly hybridized electronic state originating from the Yb f -electrons and the novel structural features (large unit cell and possible soft phonon modes) leads to high power factors and small thermal conductivity values. This demonstrates that with further optimization these systems could provide a platform for the next generation of low temperature thermoelectric materials.  more » « less
Award ID(s):
1748188
PAR ID:
10142917
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Science Advances
Volume:
5
Issue:
5
ISSN:
2375-2548
Page Range / eLocation ID:
eaaw6183
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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