IMPROVEMENT OF THERMOELECTRIC PROPERTIES IN ZN-SB ALLOYS

该研究的目的是改善ZnxSb3 （x = 3.4-4.3）合金的微观结构和热电性能，从而通过直接将热转化为电来发电。采用单轮熔融纺丝工艺制备合金，轮速为0.6 ~ 4.2 m s-1。利用x射线衍射、透射电子显微镜、能量色散x射线分析和自由能计算等方法对其微观结构进行了研究。在0.6 m s-1温度下，β-Zn4Sb3与ZnSb或Zn共存，在4.2 m s-1温度下，β- zn3sb3与ζ-Zn3Sb2共存，其中ζ-Zn3Sb2在退火带中消失。通过锌空位、间隙锌原子和β-Zn4Sb3中锌原子的反应，纳米尺度的孔洞和锌包裹体析出或消失。β-Zn4Sb3的无因次优值、功率因数、塞贝克系数、电导率和导热系数的测量取决于其复杂的微结构，这是制备工艺所特有的。

The aim of the research is to improve micro-structures and thermoelectric properties in ZnxSb3 (x = 3.4-4.3) alloys for generating power by directly converting heat into electricity.The alloys were fabricated through a single-wheel melt-spinning process at wheel velocities of 0.6-4.2 m s-1. The micro-structures were investigated using X-ray diffraction, transmission electron microscopy, together with energy dispersive X-ray analysis, and by calculating free energy. β-Zn4Sb3 in the as-spun state coexisted with ZnSb or Zn at 0.6 m s-1, while it coexisted with ζ-Zn3Sb2 in x >= 3.8 at 4.2 m s-1, where ζ-Zn3Sb2 disappeared in the annealed ribbons. Nano-scale voids and zinc inclusions precipitatedor disappeared through reactions of zinc vacancies, interstitial zinc atoms, and zinc atoms in β-Zn4Sb3.The dimensionless figure of merit, power factor, Seebeck coefficient, electrical conductivity and thermal conductivity which were measured depended on the complex micro-structures of β-Zn4Sb3 which were peculiar to the fabrication processes.