Abstract
Grain refinement has been conducted to reduce the thermal conductivity and improve the thermoelectric performance of the (Zr,Hf)NiSn based half-Heusler alloys. Nanoscale in situ precipitates were found embedded in the matrix with submicron grains. The lattice thermal conductivity was decreased due to the enhanced boundary scattering of phonons. The increased carrier concentration and electrical conductivity were observed compared to the coarse-grained alloys, which is discussed in relation to the existence of nanoscale precipitates, the effect of antisite defects, and composition change. It is suggested that the nanoscale precipitates play a significant role in the observed electrical conductivity increase.
Original language | English (US) |
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Article number | 254104 |
Journal | Applied Physics Letters |
Volume | 100 |
Issue number | 25 |
DOIs | |
State | Published - Jun 18 2012 |
Funding
We acknowledge the use of EPMA in the Key Laboratory of Submarine Geosciences, State Oceanic Administration, China. T.J.Z. would like to thank Dr. Yanzhong Pei and Heng Wang from California Institute of Technology for the valuable discussions. The work is supported by the Natural Science Foundation of China (51171171, 51061120455, and 50971115) and the Fundamental Research Funds for the Central Universities (2011QNA4034).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)