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通过水热法分别合成了Bi2Te3和Bi2Se3纳米粉末,粉末按目标产物Bi2Te2.85Se0.15混合后真空热压烧结(523～623K,50或80MPa)制成块体材料。用X射线衍射(XRD)、扫描电镜(SEM)和场发射扫描电镜对合成的粉末和块体进行了分析,对块体在室温附近的载流子浓度、迁移率、霍尔系数、以及298～598K温度区间的电导率和Seebeck系数进行了测试。在623K,80MPa,保温60min真空热压烧结得到的样品的功率因子在298K达到了峰值19.1μWcm-1K-2。探讨了烧结温度和压力对材料相结构和形貌的影响。
Bi2Te3 and Bi2Se3 nano-powders were synthesized by hydrothermal method. The powders were made into bulk materials by vacuum hot-pressing sintering (523 ~ 623K, 50 or 80MPa) according to the target product Bi2Te2.85Se0.15. The synthesized powders and aggregates were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission scanning electron microscopy (SEM). The results show that the carrier concentration, mobility, Hall coefficient, ~ 598K temperature range of the conductivity and Seebeck coefficient were tested. The power factor of the samples obtained by hot press sintering at 623K, 80MPa and holding temperature for 60min reached the peak of 19.1μWcm-1K-2 at 298K. The effects of sintering temperature and pressure on the phase structure and morphology of the material were discussed.