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Chiang, Tai-Chang Shapiro, Alan Paul 2011-06-02T16:14:35Z 2011-06-02T16:14:35Z 10000-01-01 1987 Angle-resolved photoemission spectroscopy was used to study Ag(lll) I monolayers on six different substrates: Ni(OOl), Ni(lll), Cu(OOl), Cu(lll), Au(lll), and Si(lll)-(7x7). The properties of surface states were also examined for several related systems: Cu(lll) covered by various thicknesses of Ag, and a bare Cu(332) stepped surface. Monolayer overlayers that are incommensurate with the substrate [Ag on Ni(OOl), Ni(lll), and Cu(lll)] or commensurate with the substrate only over a large unit cell [Ag on Cu(OOl)] show electronic structures essentially independent of the substrate orientation and material, except for an overall shift in binding energy. The overlayer electronic structure is somewhat different for the Ag/Au(lll) system, where there is a nearly perfect overlayer-substrate lattice match as well as substantial overlap in energy bands of like characters. In the Ag/Si system, partially disordered overlayer growth and a strongly corrugated substrate surface structure cause the overlayer features in the spectra to broaden substantially. For thicker Ag overlayers on Cu(lll), the growth mode of the Ag was determined to be layer by layer despite the large mismatch between the two lattices. The Cu(lll} surface state was observed to evolve monotonically for increasing Ag overlayer thickness to eventually become the Ag(lll) surface state. The measured rate of shift of the surface state binding energy can be explained qualitatively in terms of the degree of localization of the surface-state wave functions. For the stepped Cu(332) surface, a feature believed to be an L-gap surface state is observed just below the Fermi edge in the photoemission spectra. The properties this surface state are compared with known properties of the Cu(lll) L-gap surface state. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-02T16:14:35Z No. of bitstreams: 1 1987_shapiro.pdf: 9119907 bytes, checksum: e6eb0853a574d6e9c85368a5a885d211 (MD5) Made available in DSpace on 2011-06-02T16:14:35Z (GMT). No. of bitstreams: 1 1987_shapiro.pdf: 9119907 bytes, checksum: e6eb0853a574d6e9c85368a5a885d211 (MD5) Previous issue date: 1987 Restriction data tranferred 2014-07-01T11:13:15-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-02T16:14:36Z Item is restricted indefinitely. Thesis U of I Only 1057755 http://hdl.handle.net/2142/25219 en 1987 Alan Paul Shapiro photoemission studies thin metallic overlayer systems electronic structure Photoemission studies of thin metallic overlayer sytems Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.