热压制备(AgSbTe2)100-x．(GeTe)x合金的热电性能

Thermoelectric properties of(AgSbTe_2)_(100-x)(GeTe)_x fabricated by hot pressing method

以Pb粉、Te粉、Ag粉、Ge粉为原材料,在真空气氛下合成(AgSbTe_2)_(100-x)-(GeTe)_x(x=80-90)(TAGS)合金热电材料,X射线衍射(XRD)分析表明,热压烧结后合金具有低温菱形结构.通过热压烧结法将TAGS粉末制备成块体材料,运用XRD和扫描电子显微镜对材料的物相成分、晶体结构和形貌进行了表征.采用直流四探针法测定样品的电导率,当样品两端的温差为1—4℃的情况下测量Seebeck系数.通过材料热电性能测试,研究了30—500℃温度范围内不同组分样品性能参数的变化.结果表明,所制备的TAGS热电材料具有纳米结构,其性能随着组分的变化而变化,TAGS-80具有较好的热电性能,在530℃时具有最高热电优值(ZT=1.80).

Using pure metal Ag, Te, Ge and Sb powders as raw materials, （AgSbTe2）100-x-（GeTe）x （x = 80-90） （TAGS） are synthesized by vacuum reaction. X-ray diffraction （XRD） analysis results show that after sintering the alloys each have a rhombohedral structure. TAGS power is sintered by hot pressing method. Their phase compositions, crystal structures and morphologies are characterized by XRD and scanning electron microscope analysis methods. Their electric conductivities are measured by direct current method. Their Seebeck coefficients are measured when a temperature difference （AT = 1-4 °C） is applied along two ends of sample. Through testing the thermoelectric properties of materials, the variations of different performance parameters of the sample are investigated in a temperature range of 30-500 °C. The results show that the sample is nano crystals and its thermoelectric properties change as the composition changes. We can see that TAGS-80 has a good thermal performance, with ZTmax = 1.8 at 530 °C.