Schlecht Sabine, Erk Christoph, Yosef Maekele
Freie Universität Berlin, Institut für Chemie und Biochemie, Germany.
Inorg Chem. 2006 Feb 20;45(4):1693-7. doi: 10.1021/ic051808t.
Highly crystalline single-phase nanoparticles of the important thermoelectric materials Zn4Sb3 and ZnSb were prepared from solvochemically activated powders of elemental zinc and elemental antimony. Low-temperature reactions with reaction temperatures of 275-300 degrees C were applied using an excess of elemental zinc. The nanoscale thermoelectrics obtained were characterized by X-ray powder diffraction, transmission electron microscopy, and thermal analysis. nc-Zn4Sb3 showed particle sizes of 50-70 nm, whereas particle sizes of 15-20 nm were observed for nc-ZnSb. Calorimetric investigations showed an increased heat capacity, Cp, for nc-Zn4Sb3 with respect to the bulk material which could be reduced to the bulk value by annealing nc-Zn4Sb3 at 190 degrees C. Interestingly, nc-Zn4Sb3 showed exothermic decomposition into zinc-poorer ZnSn at 196 degrees C in an open system, indicating that Zn4Sb3 is metastable in nanocrystalline form at room temperature.
重要的热电材料Zn4Sb3和ZnSb的高度结晶单相纳米颗粒是由元素锌和元素锑的溶剂化学活化粉末制备而成的。使用过量的元素锌进行了反应温度为275 - 300摄氏度的低温反应。通过X射线粉末衍射、透射电子显微镜和热分析对所得的纳米级热电材料进行了表征。nc-Zn4Sb3的粒径为50 - 70纳米，而nc-ZnSb的粒径为15 - 20纳米。量热研究表明，相对于块状材料，nc-Zn4Sb3的热容Cp有所增加，通过在190摄氏度下对nc-Zn4Sb3进行退火处理，其热容可降低至块状材料的值。有趣的是，在开放系统中，nc-Zn4Sb3在196摄氏度时会放热分解为贫锌的ZnSn，这表明Zn4Sb3在室温下以纳米晶形式是亚稳的。
