Solid Phase Nucleation of Lead-Based Perovskites and their Properties

这是对原理研究的更新， 控制形核在α-铝过程中的应用 氧化物相变 经确定， 通过添加来控制反应的成核， 晶体学上相似的衬底（即，种子） 其中反应是外延引发的，成核 反应障碍几乎消除，潜伏期 反应时间大大缩短， 温度降低，颗粒尺寸减小。 的 目前的拨款包括研究这些原则， 铅基钙钛矿、铅镁石和铅锌 去吧。 研究的重点是外延之间的关系 晶种和混合金属氧化物前体的生长， 成核钙钛矿作为传输路径的函数， 微观结构演变和电性能。 聚合物 溶胶将被用来研究外延关系作为一个功能， 晶格失配和传输路径。种子溶胶将用于 确定转变动力学、微观结构演变和 用于制备电性能评价用试样 特性. 正在研究的材料用于电子 产业为龙头。 它们很难合成 可再现的特性。 这项研究是在 与新的加工技术有关， 温度，并潜在地改善结构的控制。 培训有经验的学生， 这些技术上重要的材料是一个重要的 补助金的组成部分。

This is the renewal of research on the principles and application of controlled nucleation during alpha aluminum oxide phase transformation. It was established that by controlling the nucleation of the reaction through the addition of crystallographically similar substrates (i.e., seeds) upon which the reaction is initiated epitaxially, the nucleation barrier to reaction is almost eliminated, the incubation period for reaction is significantly reduced, the reaction time and temperature are reduced, and the particle size is reduced. The current grant includes the study of these principles on lead-based perovskites, lead magnesium niobate and lead zinc niobate. The studies focus on the epitaxial relations between the seed crystal and mixed metal oxide precursor, growth of the nucleated perovskite as a function of transport path, microstructural evolution and electrical properties. Polymeric sols will be used to study epitaxial relations as a function of lattice mismatch and transport path. Seeded sols will be used to determine transformation kinetics, microstructural evolution and for preparation of specimens for evaluation of electrical properties. The materials being investigated are used in the electronic industry for dielectrics. They are difficult to synthesize with reproducible properties. The research under this grant is relevant to new processing techniques which lower the processing temperature, and potentially improve control of the structure. Training of students with experience to perform research on these technologically important materials is a significant component of the grant.