The Synthesis & Physical Properties of Solid State CompoundsContaining Condensed Metal Clusters Via Controlled Nucleation of Amorphous Intermediates

该建议强调新的三元钨的合成， 铌硫族化物化合物含有离散的 过渡金属原子。 这类重要的材料展示了 一系列有趣的性质，从催化活性到 磁性和超导性。 拟采用的综合办法 是基于超晶格反应物的利用， 包括分离固态反应的两个关键步骤 反应物的相互扩散，以及 产品. 向非晶态的相互扩散通过以下方式实现： 调整初始超晶格反应物的结构。 的 得到的无定形中间体的结晶是 通过化学计量和/或通过接种 与同构类似物的复合物。 材料表征 这种合成方法的进一步发展是 研究的一个重要部分是， 这些潜在的功能性材料所表现出的一系列特性 材料.

This proposal emphasizes the synthesis of new ternary tungsten and niobium chalcogenide compounds that contain discrete clusters of transition metal atoms. This important class of materials exhibits a host of interesting properties ranging from catalytic activity to magnetism and superconductivity. The synthetic approach to be used is based upon the utilization of superlattice reactants, which involves separating the two key steps of a solid-state reaction - interdiffusion of the reactant, and crystallization of the products. Interdiffusion to an amorphous state is accomplished by tailoring the structure of the initial superlattice reactant. The crystallization of the resulting amorphous intermediate is controlled via stoichiometry and/or through seeding of the composite with isostructural analogues. Materials characterization and the further development of this synthetic approach is a significant part of the proposed research, as is extending the range of properties exhibited by these potentially functional materials.