TY - JOUR
T1 - Improved Thermoelectric Performance Achieved by Regulating Heterogeneous Phase in Half-Heusler TiNiSn-Based Materials
AU - Chen, Jun Liang
AU - Liu, Chengyan
AU - Miao, Lei
AU - Gao, Jie
AU - Zheng, Yan yan
AU - Wang, Xiaoyang
AU - Lu, Jiacai
AU - Shu, Mingzheng
PY - 2018/6/1
Y1 - 2018/6/1
N2 - With excellent high-temperature stability (up to 1000 K) and favorable electrical properties for thermoelectric application, TiNiSn-based half-Heusler (HH) alloys are expected to be promising thermoelectric materials for the recovery of waste heat in the temperature ranging from 700 K to 900 K. However, their thermal conductivity is always relatively high (5–10 W/mK), making it difficult to further enhance their thermoelectric figure-of-merit (ZT). In the past decade, introducing nano-scale secondary phases into the HH alloy matrix has been proven to be feasible for optimizing the thermoelectric performance of TiNiSn. In this study, a series of TiNiSn-based alloys have been successfully synthesized by a simple solid-state reaction. The content and composition of the heterogeneous phase (TiNi2Sn and Sn) is accurately regulated and, as a result, the thermal conductivity successfully reduced from 4.9 W m−1 K−1 to 3.0 Wm−1 K−1 (750 K) due to multi-scale phonon scattering. Consequently, a ZT value of 0.49 is achieved at 750 K in our TiNiSn-based thermoelectric materials. Furthermore, the thermal stability of TiNiSn alloys is enhanced through reducing the Sn substance phase.
AB - With excellent high-temperature stability (up to 1000 K) and favorable electrical properties for thermoelectric application, TiNiSn-based half-Heusler (HH) alloys are expected to be promising thermoelectric materials for the recovery of waste heat in the temperature ranging from 700 K to 900 K. However, their thermal conductivity is always relatively high (5–10 W/mK), making it difficult to further enhance their thermoelectric figure-of-merit (ZT). In the past decade, introducing nano-scale secondary phases into the HH alloy matrix has been proven to be feasible for optimizing the thermoelectric performance of TiNiSn. In this study, a series of TiNiSn-based alloys have been successfully synthesized by a simple solid-state reaction. The content and composition of the heterogeneous phase (TiNi2Sn and Sn) is accurately regulated and, as a result, the thermal conductivity successfully reduced from 4.9 W m−1 K−1 to 3.0 Wm−1 K−1 (750 K) due to multi-scale phonon scattering. Consequently, a ZT value of 0.49 is achieved at 750 K in our TiNiSn-based thermoelectric materials. Furthermore, the thermal stability of TiNiSn alloys is enhanced through reducing the Sn substance phase.
KW - half-Heusler
KW - heterogeneous phase
KW - Thermoelectric materials
KW - TiNiSn alloys
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U2 - 10.1007/s11664-017-6013-8
DO - 10.1007/s11664-017-6013-8
M3 - Article
AN - SCOPUS:85037998197
VL - 47
SP - 3248
EP - 3253
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
SN - 0361-5235
IS - 6
ER -