Abstract—

We have worked out conditions for the preparation of microcrystalline n-type lead telluride-based materials doped with lead iodide and investigated their microstructure and thermoelectric properties. The materials were prepared by hot-pressing powders produced by grinding an ingot to a particle size on the order of hundreds of microns in a planetary mill and to a particle size under hundreds of nanometers (mechanical activation) and by melt spinning. Fracture surfaces of the hot-pressed samples were examined on an optical and a scanning electron microscope. All of the samples had a nonuniform microstructure, with both small and larger grains present. In the samples prepared from the powders produced by mechanical activation, nanograins were detected. We have measured the Seebeck coefficient, electrical conductivity, and thermal conductivity of the samples at room temperature and in the range 300–800 K and evaluated their lattice thermal conductivity and thermoelectric figure of merit, ZT. Their lattice thermal conductivity was shown to decrease with decreasing grain size. The highest thermoelectric figure of merit, (ZT)_max = 1.32 at 630 K, was offered by the materials produced from the mechanically activated powder.

中文翻译：

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微晶碲化铅的制备及热电性能

摘要-

我们已经制定了条件微晶的准备ñ掺杂有碘化铅的一种类型的碲化铅基材料，并研究了它们的微观结构和热电性能。通过热压粉末来制备材料，所述粉末是通过将锭料在行星式磨机中研磨成数百微米的粒度，数百纳米以下的粒度（机械活化）而制成的，并通过熔融纺丝制成。在光学显微镜和扫描电子显微镜下检查热压样品的断裂表面。所有样品均具有不均匀的微观结构，同时存在小晶粒和大晶粒。在通过机械活化产生的粉末制备的样品中，检测到纳米颗粒。我们已经测量了塞贝克系数，电导率，ZT。它们的晶格热导率显示出随着晶粒尺寸的减小而降低。由机械活化粉末生产的材料可提供最高的热电性能因数（ZT）_max = 1.32在630K。