Ti掺杂对half-Heusler合金YNiSb热电性能的影响  

Effect of Ti Doping on the Thermoelectric Properties of YNiSb Half-Heusler Alloy

作　　者：肖凯[1] 朱铁军[1] 蔚翠[1] 杨胜辉[1] 赵新兵[1] 

机构地区：[1]浙江大学材料科学与工程系硅材料国家重点实验室,浙江杭州310027

出　　处：《材料科学与工程学报》2011年第2期187-190,209,共5页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(50971115);浙江省科技厅基金资助项目(2009C34007)

摘　　要：通过悬浮熔炼方法制备了Y1-xTixNiSb(x=0,0.015,0.02,0.025)材料并研究了Ti掺杂对材料热电性能的影响。经过孔隙率修正后,Ti掺杂样品的热导率和电导率均比未掺杂样品要低,并且随着Ti含量的增加呈现先下降后上升的趋势。分析发现Ti掺杂后样品热导率的降低是由于电子热导率的下降所致,电子载流子的引入则导致了电导率的下降。Ti掺杂后样品Seebeck系数在室温下有变负趋势,表明材料在室温下可能呈现N型传导特性。最终,Ti掺杂提高了材料的热电性能。Ti含量x=0.015的样品在770K左右获得最大ZT值0.085,与未掺杂样品相比,提高了约60%。Levitation melting has been used to fabricate Y_1-xTi_xNiSb（x=0,0.015,0.02,0.025） half-Heusler compounds and the effect of Ti doping on the thermoelectric properties has been investigated.As the Ti content increases,the thermal conductivity and the electrical conductivity of the samples decrease firstly and then increase.The decrease of the thermal conductivity is mainly due to the reduction of electronic thermal conductivity.The Seebeck coefficient of the doped samples turns to negative when the temperature is below room temperature,which indicates that the material may show n-type conduction below room temperature.Finally,the thermoelectric properties of the materials have been improved by Ti doping.The maximum ZT value of about 0.085 was obtained at 770K for the sample with x=0.015,which increases about 60% compared with that of the undoped one.

关 键 词：热电材料 热导率 电导率 悬浮熔炼 

分 类 号：TG146.15[一般工业技术—材料科学与工程]