Flux Syntheis and Properties of New Crystalline and Glassy Chalcogenides

本项目的目标是合成和表征金属硫代磷酸盐和硒磷酸盐家族的新型固态材料。金属硫代磷酸盐和硒磷酸盐表现出非常丰富的化学成分，它基于通过简单的原位熔融在磷酸盐熔剂中形成的阴离子，这些阴离子充当基本的结构构建块。有待探索的领域包括无碱金属的三元金属和稀土金属硫代磷酸盐和硒磷酸盐，相应的碱金属四元衍生物，以及由这些材料操纵形成的玻璃。硫代砷酸盐和硒砷酸盐熔剂也将被探索，以发现相应的砷化合物。对新材料的表征将包括用单晶X射线散射法确定结构，以及测量光学吸收、热行为和电导率等物理性质。用对分布函数(PDF)分析方法对玻璃的结构进行了探讨。为了了解磷酸盐熔剂中形成的阴离子的识别、分布和化学，本项目中的反应性溶剂熔融碱式多硫代磷酸和多硒磷酸盐将通过核磁共振波谱进行研究。最终，我们希望控制合成目标化合物中特定构建块的稳定和掺入。这一研究项目的最终目的是增强我们对硫化物化学的了解，使化学更具可控性和可预测性，从而设计出有用的新材料。该项目有一个非常强大的教育组成部分，旨在教育学生在固体合成的高级学科，包括非氧化物材料的发现和新的最先进的实验室技术。发现新的组成和结构的固体材料，以及了解它们的化学行为和物理性质，如光学和电子行为，对工业非常重要。例如，玻璃版本的金属硫代磷酸盐和硒磷酸盐表现出可控的无定形到晶相的变化，并可能具有存储应用的潜力。在这些领域接受培训的学生将充分利用目前和未来的学术和工业就业机会。

The goal of this project is to synthesize and characterize new solid-state materials in the metal thiophosphate and selenophosphate families. The metal thiophosphate and selenophosphates show a very rich chemistry that is based on anions that form in chalcophosphate fluxes by simple in-situ fusion, and these act as fundamental structural building blocks. Areas to be explored include alkali metal-free ternary metal-and rare-earth-metal- thiophosphates and selenophosphates, corresponding alkali metal quaternary derivatives and also glasses formed from the manipulation of these materials. Thioarsenate and selenoarsenate fluxes will also be explored to discover corresponding arsenic compounds. Characterization of the new materials will include structural determinations by single-crystal X-ray scattering methods and the measurement of physical properties such as optical absorption, thermal behavior and electrical conductivity. The structure of glasses will be probed with pair distribution function (PDF) analysis. The molten alkali poly-thiophosphate and poly-selenophosphate salts, which are the reactive solvents in this project, will be studied by Nuclear Magnetic Resonance spectroscopy in order to understand the identity, distribution, and chemistry of the anions that form in chalcophosphate fluxes. Eventually we wish to control the stabilization and incorporation of specified building blocks in synthetic target compounds. The ultimate goal of this research project is to enhance our knowledge of the chemistry of chalcogenides and render the chemistry more controllable and predictable so useful new materials can be designed. This project has a very strong education component that aims to educate students in the advanced subject of solid state synthesis including non-oxide materials discovery and novel state-of the-art laboratory techniques.The discovery of new classes of solid state materials with novel composition and structure, as well as an understanding of their chemical behavior and physical properties such as optical and electronic behavior are important to industry. For example, the glass versions of the metal-thiophosphate and -selenophosphates show controllable amorphous to crystal phase changes and may have potential for memory storage applications. Students trained in these areas are well poised to exploit current and future academic and industrial job opportunities.