Hf掺杂BiSbTe_3结构与热电性能研究

Structure and thermoelectrical properties of Hf doped BiSbTe_3 compounds

以高纯Hf、Bi、Sb和Te为原料,在1000℃下,经10h氩气保护熔融状态下反应,冷却球磨制粉,再在氮气保护下进行热压(450℃,20MPa),成功制备出一系列不同Hf掺杂量的Hf2x(Bi,Sb)2-2xTe3化合物.X射线粉末衍射Rietveld分析说明,Hf在结构中占据6c晶位,以替代(Bi,Sb)的形式进入晶格.Hf掺杂引起BiSbTe3的Seebeck系数增大,电导率降低.功率因子在375K时达最大值526μW/mK2.

A series of Hf-doped of Hf2x （Bi, Sb）2-2xTe3 compounds were prepared at 1000 ℃ for 6 h by the reaction of the high purity metals Hf, Bi, Sb and Te in a sealed quartz tube under an argon gas environment, followed by a powder metallurgy hot-press process （450 ℃ , 20 MPa） under the protection of flowing nitrogen. X-ray powder diffraction Rietveld refinement shows that Hf substitutes Bi and Sb in the structure of （Bi, Sb）2Te3 and occupies the 6c crystal position. The thermoelectric property measurements show that the Seebeck coefficient increases and the electrical conductivity slightly decreases with doping of Hf. The highest power factor α^2σ is 526 μW/mK^2 at 375 K forx = 0.02.