Microstructures and Thermoelectric Properties of an Annealed Ti0.5(Hf0.5Zr0.5)0.5NiSn0.998Sb0.002 Ribbon
Microstructures and Thermoelectric Properties of an Annealed Ti0.5(Hf0.5Zr0.5)0.5NiSn0.998Sb0.002 Ribbon
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DOI：
10.1007/s11664-009-0773-8
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发表时间：
2009-04
影响因子：
2.1
通讯作者：
T. Morimura;M. Hasaka;Syotaroh Yoshida;H. Nakashima
中科院分区：
文献类型：
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作者：
T. Morimura;M. Hasaka;Syotaroh Yoshida;H. Nakashima
采用旋转浇铸法制备了Ti0.5（Hf0.5Zr0.5）0.5NiSn0.998Sb0.002半赫斯勒热电材料，室温下的ZT随退火时间的延长而增加，但电导率却随退火时间的延长而降低，在1050 K退火48 h后，ZT达到0.10。在粉末X射线衍射分析中，每个半赫斯勒峰伴随着在高角度侧的凸起，对应于次要的富钛半赫斯勒相。次要相的数量和Ti成分随着退火时间的增加而增加，尽管主要的半Heusler相的数量和Ti成分几乎是恒定的。在透射电子显微镜分析中，观察到几个纳米大小的颗粒状畴，具有原子有序或无序。热处理通过富钛和贫钛半赫斯勒晶粒和颗粒畴的异质微结构的生长来显著改善热电性能。
The thermoelectric half-Heusler compound Ti0.5(Hf0.5Zr0.5)0.5NiSn0.998Sb0.002was fabricated by spin-casting and subsequent annealing.ZTat room temperature increased with annealing time through an increase in absolute Seebeck coefficients despite a decrease in electrical conductivity.ZTreached 0.10 after annealing at 1050 K for 48 h. In powder x-ray diffraction analysis, each half-Heusler peak was accompanied by a bump at the high-angle side, corresponding to a minor Ti-rich half-Heusler phase. The quantity and Ti composition of the minor phase increased with annealing time, although those of the major half-Heusler phase were almost constant. In transmission electron microscopic analysis, granular domains, several nanometers in size, with atomic ordering or disordering were observed. Thermoelectric properties were␣improved by annealing through the growth of heterogeneous microstructures of the Ti-rich and Ti-poor half-Heusler grains and of the granular domains.