Low Temperature Synthesis and Electrical Characterization of Solid Chalcogenides using Molten Salts

将使用熔融多硫化物盐和水热技术来探索在中低温下合成新的硫化物材料。这两种合成技术都将在与后过渡金属和主族元素的反应中使用各种A2Qx盐。将研究温度在200-500摄氏度之间的反应，因为以前很少有人探索这个范围。已经证明，在这个温度范围内，具有新结构类型的新材料可以形成和结晶。硫、硒和碲在二维和三维上连接不同亚结构的非凡能力，以及相对较低的温度为合成非常大量的新化合物提供了一个有利的机会。这些新化合物的物理性质有待探索，包括磁性、随温度变化的吸附和氧化还原性质。为了探索不寻常的电子现象，我们将通过变温四探针电阻率和热电势(Seebeck)测量来详细研究新化合物的电荷输运性质。测量将主要在单晶样品上进行。这笔赠款由材料研究部和化学部共同支持。

Molten polychalcogenide salt and hydrothermal techniques will be used to explore the synthesis of new chalcogenide materials at low and intermediate temperatures. Both synthetic techniques will use various A2Qx salts in reactions with late transition metals and main-group elements. Reactions at temperatures between 200-500 oC will be studied because this range has been little explored previously. It has been demonstrated that in this temperature range new materials with new structure types can form and crystallize. The remarkable ability of sulfur, selenium, and tellerium to bridge different sub-structures in two and three dimensions, and the relatively low temperatures provide a lucrative opportunity for synthesis of a very large number of new compounds. Physical properties of these new compounds to be explored include magnetic, sorption as a function of temperature, and redox properties. In order to probe unusual electronic phenomena, the charge transport properties of the new compounds will be studied in detail via variable temperature four-probe resistivity as well as thermoelectric power (Seebeck) measurements. The measurements will be primarily done on single crystal samples. This grant is jointly supported by the Division of Materials Research and Chemistry Division.