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

熔融多硫系盐和水热技术将用于探索在低温和中低温下合成新的硫系材料。两种合成技术都将使用各种A2Qx盐与后期过渡金属和主族元素反应。将研究温度在200-500℃之间的反应，因为这个范围以前很少被探索。研究表明，在此温度范围内可以形成和结晶具有新结构类型的新材料。硫、硒和碲在二维和三维空间上桥接不同亚结构的非凡能力，以及相对较低的温度，为合成大量新化合物提供了有利的机会。这些有待探索的新化合物的物理性质包括磁性、随温度变化的吸附性和氧化还原性。为了探测不寻常的电子现象，将通过变温四探针电阻率和热电功率（塞贝克）测量来详细研究新化合物的电荷输运特性。测量将主要在单晶样品上进行。本基金由材料研究部及化学部共同资助。

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.