Hydrogen Phase Behavior in Thin-Film Metals

9982520 Heuser该程序旨在提供一套全面的实验和模拟数据的氢在薄金属膜。该计划解决了薄膜金属中氢相行为的各个方面，建立在最近的氢金属系统的调查。 采用对金属晶格中的氢具有上级灵敏度的中子散射技术来测量薄膜几何形状中的压力-成分-温度或PCT行为、弹性响应、溶质深度分布和沉淀形态。 X射线衍射分析用于确定晶格应变和相干性损失。 透射电子显微镜分析表征位错亚结构。 数值模拟模型晶格膨胀，溶质偏析，基板膜的相互作用，和沉淀形态。 本研究选择的系统包括模型金属，如外延Pd和Nb，以及更多的应用特定的系统，如Pd合金和稀土沉积。 这些结果有望使人们对氢-金属系统的基本性质有更全面的了解。许多氢相关的应用已经确定为薄金属膜，包括氢传感器，电池电极和可切换的镜子。 金属薄膜在工业上的应用是近年来氢效应研究的一个重要推动因素。薄膜PCT行为，弹性响应，晶格应变状态之间的关系需要仔细研究，以促进理解氢薄金属膜系统。 此外，薄膜几何形状的氢化物沉淀形态的测量从未进行过。该测量将在单晶（外延）Pd膜中进行，并与块状单晶Pd中氢化物形态的测量进行比较。*

9982520HeuserThis program has been designed to provide a comprehensive set of experimental and simulation data of hydrogen in thin metal films. The program addresses all aspects of hydrogen phase behavior in thin film metals, building on recent investigations of hydrogen-metal systems. Neutron scattering techniques with superior sensitivity to hydrogen in metal lattices are employed to measure the pressure-composition-temperature or PCT behavior, elastic response, solute depth profile, and precipitation morphology in thin-film geometry. X-ray diffraction analysis is used to determine lattice strain and coherency loss. Transmission electron microscopy analysis characterizes dislocation substructure. Numerical simulations model lattice expansion, solute segregation, substrate-film interactions, and precipitation morphology. The systems chosen for this study include model metals, such as epitaxial Pd and Nb, and more application-specific systems, such as Pd alloys and rare earth depositions. The results are expected to lead to a more complete understanding of fundamental properties of hydrogen-metal systems. %%%Many hydrogen-related applications have been identified for thin metal films, including hydrogen sensors, battery electrodes, and switchable mirrors. The development of thin metal films for industrial applications has been a motivating factor in many recent investigations of hydrogen effects. Careful studies of the relationship between film PCT behavior, the elastic response, and the lattice strain state are needed to advance understanding of hydrogen-thin metal film systems. In addition, a measurement of hydride precipitation morphology in thin film geometry has never been made. This measurement will be made in single crystal (epitaxial) Pd films and compared to measurements of the hydride morphology in bulk single crystal Pd.***