Uncovering high thermoelectric figure of merit in (Hf,Zr)NiSn half-Heusler alloys
Uncovering high thermoelectric figure of merit in (Hf,Zr)NiSn half-Heusler alloys
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DOI：
10.1063/1.4927661
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发表时间：
2015-07-27
影响因子：
4
通讯作者：
Poon, S. J.
中科院分区：
文献类型：
--
作者：
Chen, L.;Gao, S.;Poon, S. J.
Half-Heusler 合金（MgAgSb 结构）是有前途的热电材料。 RNiSn 半 Heusler 相（R = Hf、Zr 和 Ti）从热稳定性角度来看是研究最多的。在类似于 450-900 摄氏度的温度范围内获得的最高无量纲品质因数 (ZT) 类似于 1，主要在纳米结构合金中实现。通过适当的退火，在没有纳米结构的情况下，在类似于1n型(Hf,Zr)NiSn相的先前ZT中获得了类似于1.2的ZT。功率因数显着增加，载流子密度降低，载流子迁移率增加。这些发现归因于结构秩序的改善。本方法可用于优化霍斯勒型合金的功能特性。 (C) 2015 AIP 出版有限责任公司。
Half-Heusler alloys (MgAgSb structure) are promising thermoelectric materials. RNiSn half-Heusler phases (R = Hf, Zr, and Ti) are the most studied in view of thermal stability. The highest dimensionless figure of merit (ZT) obtained is similar to 1 in the temperature range similar to 450-900 degrees C, primarily achieved in nanostructured alloys. Through proper annealing, ZT similar to 1.2 has been obtained in a previous ZT similar to 1 n-type (Hf,Zr)NiSn phase without the nanostructure. There is an appreciable increase in power factor, decrease in charge carrier density, and increase in carrier mobility. The findings are attributed to improved structural order. Present approach may be applied to optimize the functional properties of Heusler-type alloys. (C) 2015 AIP Publishing LLC.