Description: Work under this grant focused on the use of photoelectron emission as a probe of deformation processes in metals, principally single crystal and polycrystalline aluminum. Dislocations intersecting the surface produce patches of low work function metal which emit electrons when illuminated with the appropriate ultraviolet radiation. We have shown that changes in the photoemission signals during deformation can be used to identify the onset of strain localization. In some systems, the photoelectron kinetic energy distribution reflects the distribution of surface orientations, which depends on the competition between grain rotation and slip. Photoemission electron microscope images of shape memory alloys and thin films show marked changes in intensity and surface topography as the materal passes through its transition temperature. Photoelectron emission provides important information on the temporal progress of deformation processes that complements the spatial information provided by other techniques.
Date: September 28, 2007
Creator: Dickinson, J. Thomas
Partner: UNT Libraries Government Documents Department