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以单质B i,Sb和Te粉末为原材料,通过真空电弧等离子体蒸发法合成了(B ixSb1-x)2Te3热电粉末材料。采用X射线衍射(XRD)、能谱分析(EDS),场发射扫描电子显微术(FE-SEM),透射电子显微术(TEM)和选区电子衍射(SAED)分析方法对(B ixSb1-x)2Te3粉末材料的物相结构、成分和形貌进行了表征。XRD图谱的3强衍射峰分别为(015),(1010)和(110),(B ixSb1-x)2Te3纳米粉末的XRD图谱与标准XRD图谱峰(49-1713)相对应,宽化的衍射峰表明了粉末的晶粒具有纳米尺度。能谱定量分析表明B i和Sb的原子百分比分别为18.1%,20.3%,两者原子百分比之和为38.4%,Te的原子百分比是61.6%。场发射扫描电子显微分析表明纳米粉末颗粒尺寸比较均匀,粉末存在团聚现象,大多数粉末都呈椭球形。透射电子显微分析表明(B ixSb1-x)2Te3纳米粉末的平均粒径约为50 nm,粉末呈不规则的多面体结构,还有一些薄片状和棒状的结构,这与B i2Te3基半导体化合物的高度各向异性是一致的。(B ixSb1-x)2Te3纳米粉末的选区电子衍射图表明每一个颗粒是由许多小晶核组成的,证明了颗粒是以纳米尺度生长。由于晶粒取向随机,且晶粒细小引起有许多衍射斑组成的衍射环的宽化,揭示了(B ixSb1-x)2Te3纳米粉末的多晶结构。
(B ixSb1-x) 2Te3 thermoelectric powder was synthesized by vacuum arc plasma evaporation using elemental B i, Sb and Te powders as raw materials. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) x) 2Te3 powder material phase structure, composition and morphology were characterized. The XRD patterns of XRD patterns were (015), (1010) and (110) respectively. The XRD pattern of (BixSb1-x) 2Te3 nanopowders corresponded to the standard XRD patterns (49-1713) Peaks indicate that the grains of the powder have nanoscale dimensions. Quantitative chemical analysis showed that the atomic percentages of B i and Sb were 18.1% and 20.3%, respectively. The sum of atomic percentages was 38.4% and the atomic percentage of Te was 61.6%. Field emission scanning electron microscopy analysis showed that the nano-powder particle size is relatively uniform, there is agglomeration of powder, most of the powder are ellipsoidal. Transmission electron microscopy analysis showed that the average particle size of (BixSb1-x) 2Te3 nanopowder was about 50 nm, the powder was irregular polyhedron structure, and some flaky and rod-shaped structure, which was in agreement with the B i2Te3-based semiconductor compound Highly anisotropic is consistent. The selected area electron diffraction patterns of (BixSb1-x) 2Te3 nanopowders indicate that each particle is composed of many small nuclei, demonstrating that the particles grow on a nanometer scale. Due to the random grain orientation and the small grain size, the polycrystalline structure of (BixSb1-x) 2Te3 nanopowders is revealed.