具有花状形貌Lu_(x)Bi_(2-x)Te_(3)合金的制备及性能  

Preparation and thermoelectric properties of the Lu_(x)Bi_(2-x)Te_(3)alloys with nanoflower morphology

作　　者：吴芳 王伟 WU Fang;WANG Wei(College of Artificial Intelligence,Henan Finance University,Zhengzhou 450046,China;College of Information Engineering,Zhengzhou University of Technology,Zhengzhou 450044,China)

机构地区：[1]河南财政金融学院人工智能学院,河南郑州450046 [2]郑州工程技术学院信息工程学院,河南郑州450044

出　　处：《河北大学学报（自然科学版）》2023年第1期58-66,共9页Journal of Hebei University(Natural Science Edition)

基　　金：河南省重点科技攻关项目(212102210599)。

摘　　要：Bi_(2)Te_(3)基材料在室温附近具有良好的热电性能,通过掺杂和纳米技术可以提高Bi_(2)Te_(3)基热电材料的热电性能,其主要由热电优值(ZT)决定.本文通过水热法成功制备了具有纳米花形貌的Lu_(x)Bi_(2-x)Te_(3)粉体,并对制备的纳米粉体分别进行XRD和SEM表征,讨论了Lu元素掺杂和乙二胺四乙酸(EDTA)用量对Lu_(x)Bi_(2-x)Te_(3)纳米花粉体形貌的影响,结果表明:Lu元素掺杂不利于纳米花形貌的形成,而EDTA用量的合适选取对于纳米花形貌的形成起着至关重要的作用.接着采用热压法将Lu_(x)Bi_(2-x)Te_(3)纳米花粉体压制成致密块体,讨论了Lu元素掺杂对Lu_(x)Bi_(2-x)Te_(3)块体热电性能的影响,结果表明:Lu掺杂和纳米花形貌有利于提高样品的功率因子同时保持较低的热导率,从而可以达到较高的ZT值;Lu_(0.2)Bi_(1.8)Te_(3)样品和Lu_(0.25)Bi_(1.75)Te_(3)样品的ZT值均高于区域熔炼商用Bi_(2)Te_(3)块体的值,并且Lu_(0.25)Bi_(1.75)Te_(3)样品的ZT值在测温范围内均高于1,其ZT值在473 K时达到了1.14,高于其他相关报道的n型块体的值.这一研究为提高Bi_(2)Te_(3)基合金热电材料的热电性能提供了一个新的途径.The Bi_(2)Te_(3)based materials have good thermoelectric properties around room temperatures.The themoelectric properties of the Bi_(2)Te_(3)based alloys can be improved by nanotechnology and element doping.In this paper the Lu_(x)Bi_(2-x)Te_(3)nanopowders with nanoflowers morphology were synthesize by hydrothermal method,and the phase structure and micro-topography of the nanopowders were investigated by X-ray diffractometer(XRD)and a field-emission scanning electron microscopy(FESEM).The effects of the Lu doping and the ethylene diamine tetraacetic acid(EDTA)amounts on the morphology of the nanopowders were investigated.The results showed that the Lu doping is not beneficial to form nanoflowers morphology,and it is vital to select proper amounts of EDTA for forming nanoflowers morphology of the nanopowders.Subsequently,the Lu_(x)Bi_(2-x)Te_(3)bulk were synthesized by hot pressing method,and the effects of the Lu doping on the thermoelectric properties of the Lu_(x)Bi_(2-x)Te_(3) bulk were also investigated.The results showed that the Lu doping and the nanoflowers morphology are helpful to increase the power factor and are also helpful to keep lower thermal conductivity,leading to a high ZT value.The ZT values of the Lu_(0.2)Bi_(1.8)Te_(3)and Lu_(0.25)Bi_(1.75)Te_(3)sample are all higher than the commercial zone melting Bi_(2)Te_(3)ingots.And the ZT values of the Lu_(0.25)Bi_(1.75)Te_(3)sample are all higher than 1 in the whole testing temperature range,and the optimum value reached 1.14 at 473 K which is higher than that of other reported n type Bi_(2)Te_(3).This study provides a new way to improve the thermoelectric properties of the Bi_(2)Te_(3)based alloys.

关 键 词：Lu_(x)Bi_(2-x)Te_(3)粉体 Lu元素掺杂 EDTA用量 纳米花形貌 热电性能 

分 类 号：TG146.4[一般工业技术—材料科学与工程]