銻元素摻雜對Ti0.5Zr0.5NiSn1-xSbx多元合金熱電性質之影響

Effect of Sb doping on the thermoelectric properties of Ti0.5Zr0.5NiSn1-xSbx multi-element alloys

吳皇南(Hung-Nan Wu)

指導教授 ： 廖建能

國立清華大學/工學院/材料科學工程學系/碩士(2006年)

https://doi.org/10.6843/NTHU.2006.00506

摘要

本研究以具half-Heusler結構的Ti0.5Zr0.5NiSn四元合金為基礎，探討Ti0.5Zr0.5NiSn1-xSbx五元合金系統經高溫熱處理之後，不同銻成分摻雜比例(x=0~0.5)對於合金熱電性質的影響。實驗結果顯示在室溫條件下，退火前後Seebeck係數絕對值與電阻係數皆隨銻摻雜成份增加而降低。即使是微量添加銻元素，合金電阻係數變化亦相當顯著。分析亦發現成分為x=0.005經熱處理的試片具有最大的功率因子(S2/λ，Power factor) 2.83×10-3W/m-K2。相較於Ti0.5Zr0.5NiSn合金的功率因子0.72×10-3W/m-K2上升約三倍多。在室溫下，x=0.005成份的合金可得最大的ZT值約為0.16，比起Ti0.5Zr0.5NiSn合金的ZT值提升了四倍。此結果説明了銻元素微量添加對於此合金系統的熱電性能具有正面幫助。另外，高溫熱電性質量測結果顯示，Seebeck係數絕對值會隨溫度升高而有上昇之趨勢，摻雜後的試片電阻係數亦隨溫度升高而上昇，表示銻元素摻雜將會使得合金的傳導性質偏向金屬性。綜合而言，低於錫、銻原子百分比總和5 % 之銻元素摻雜對於Ti0.5Zr0.5NiSn1-xSbx合金系統之熱電性質提升有正面的效果。

關鍵字

銻 ； 摻雜 ； 合金 ； 熱電 ； 半赫斯勒

並列摘要

A effect of Sb doping (x=0~0.5) on the thermoelectric properties of annealed Ti0.5Zr0.5NiSn1-xSbx multi-element alloys is studied based on Ti0.5Zr0.5NiSn quaternary alloy with half-Heusler structure. The result shows both the absolute value of Seebeck coefficient and electrical resistivity decrease as the quantity of Sb doping increases at room temperature. The change of resistivity is marked for the alloy with slight Sb doping. The maximum power factor(S2/λ) is 2.83×10-3W/m-K2 for the annealed Ti0.5Zr0.5NiSn1-xSbx (x=0.005) alloy. It is three times larger than that of Ti0.5Zr0.5NiSn which is 0.72×10-3W/m-K2. The maximum ZT value is about 0.16 for the Ti0.5Zr0.5NiSn1-xSbx (x=0.005) alloy at room temperature which is four times larger than that of Ti0.5Zr0.5NiSn. Therefore, the lightly Sb doping would dramatically improve the thermoelectric properties of the Ti0.5Zr0.5NiSn alloy system. Besides, the results of thermoelectric properties measurement at high temperature reveal that the absolute value of Seebeck coefficient increases as the temperature rises. The resistivity of Sb doped alloys increases with rising temperature, indicating that the Sb doping would promote the metallic transport properties. Consequently, a slight Sb doping (below 5at% substitution of Sn atoms)would enhance the thermoelectric properties of Ti0.5Zr0.5NiSn1-xSbx alloy system.

並列關鍵字

Sb ； doping ； alloy ； thermoelectric ； half-Heusler

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