Thermoelectric Properties of Directionally Solidified Half-Heusler (M 0.5 a ,M 0.5 b )NiSn (Ma, Mb = Hf, Zr, Ti) Alloys
Thermoelectric Properties of Directionally Solidified Half-Heusler (M 0.5 a ,M 0.5 b )NiSn (Ma, Mb = Hf, Zr, Ti) Alloys
复制标题
DOI：
10.1007/s11664-009-0710-x
复制
发表时间：
2009-07-01
影响因子：
2.1
通讯作者：
Mishima, Yoshinao
中科院分区：
文献类型：
--
作者：
Kimura, Yoshisato;Ueno, Hazuki;Mishima, Yoshinao
为了评价M位原子Ti、Zr和Hf的替代对热电性能的影响，采用定向凝固法制备了近单相（M（0.5）（a），M（0.5）（B））NiSn合金（M-a，M-B = Hf，Zr，Ti）。在（Ti-0.5，Hf-0.5）NiSn合金中，由于Ti和Hf的原子尺寸和原子质量的差异最大化，晶格热导率可以最有效地降低，这可能是由于固溶体效应。此外，通过显微组织观察、化学成分测定和X射线衍射分析，发现了（Ti-0.5，Hf-0.5）NiSn和（Ti-0.5，Zr-0.5）NiSn合金中富Ti和贫Ti半Heusler相的相分离。
To evaluate the effect of the substitution of the M-site atoms Ti, Zr, and Hf on thermoelectric properties, nearly single-phase (M (0.5) (a) ,M (0.5) (b) )NiSn alloys (M-a, M-b = Hf, Zr, Ti) were fabricated by directional solidification. The lattice thermal conductivity can be most effectively reduced in the (Ti-0.5,Hf-0.5)NiSn alloy, probably due to the solid-solution effect, since the difference in atomic size and atomic mass are maximized between Ti and Hf. Moreover, we have found the phase separation between Ti-rich and Ti-poor half-Heusler phases in (Ti-0.5,Hf-0.5)NiSn and (Ti-0.5,Zr-0.5)NiSn alloys through observation of microstructure, chemical concentration measurement, and x-ray diffractometry.