title: Formation of self-assembled nanoplates via hydrogenation of epitaxial Pd film.
abstract: Understanding the relationship between the uptake of hydrogen gas and hydride phase formation and evolution in metal solids is a phenomenon of significant technological importance due to current development of hydrogen storage devices, sensors, and membranes. The performance of these devices is degraded by structural defect formation during incoherent metal-hydride phase transformation. In this work, atomic force and scanning electron microscopy reveal formation of nanoplates along the ⟨111⟩ directions in a (111) epitaxial Pd film. These nanostructures are observed after high temperature and high pressure gas phase hydrogenation and cooling in ambient temperature. Transmission electron microsocpy (TEM) analysis of a posthydrogenated film did not show considerable plastic deformation. The size of the nanoplates increased with increasing Pd film thickness. A formation mechanism of nanoplates is proposed: cooling the sample reactor in ambient temperature after hydrogen loading induced formation of coherent or partially coherent β-phase plates along {100} planes corresponding to minimum elastic energy of interaction between metal and hydride phases.
authors.affiliation: Department of Mechanical Engineering, University of Maryland , 2181 Glenn L. Martin Hall, Bldg 088, College Park, Maryland 20742, United States.
authors.forename: Brad M
authors.initials: BM
authors.lastname: Boyerinas
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Roytburd
authors.forename: Hugh A
authors.initials: HA
authors.lastname: Bruck