Role of Grain Structure and Grain Boundary Diffusion in Thin Film Reactions

小行星9308651 本计画探讨不同厚度及微结构之铌铝化物多晶薄膜之晶粒结构及晶界扩散。 用量热法和透射电镜研究了Nb_3Al的形成动力学。 Nb 3Al形成的模型将根据形状，生长速率和成核密度的测量进行修改。 成核位点将与反应物层的微观结构特征相关联。 Nb 3-xAl相的组成的直接测量将由分析电子显微镜。 随着Nb 3Al层的总边界面积的增加，Nb 3-xAl相的Al浓度的增加应该为晶界扩散在反应中的作用提供直接证据。 %%% 这项研究与微电子和磁性薄膜工业中使用的薄膜器件有关。 ***

9308651 Barmak This project examines grain structure and grain boundary diffusion in thin film niobium aluminide polycrystalline films of different thicknesses and microstructures. The kinetics of Nb3Al formation are studied with calorimetry and transmission electron microscopy. A model for the Nb3Al formation will be modified based on the measurements of shape, growth rate, and nucleation density. Nucleation sites will be linked to microstructural features of the reactant layers. Direct measurements of the composition of Nb3-xAl phase will be made by analytical electron microscopy. An increase in the Al concentration of the Nb3-xAl phase with an increase in the total boundary area of the Nb3Al layer should provide direct evidence for the role of grain boundary diffusion in the reaction. %%% This research has relevance to thin film devices used in the microelectronic and magnetic thin film industries. ***