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Series

1984

University of Nebraska - Lincoln

Peter Dowben Publications

Articles 1 - 2 of 2

Full-Text Articles in Physics

Segregation Of Copper To The Surface Of Copper-Nickel Alloys, Peter A. Dowben Dec 1984

Segregation Of Copper To The Surface Of Copper-Nickel Alloys, Peter A. Dowben

Peter Dowben Publications

Copper segregation profiles at the surfaces of Cu17Ni83(111) and Cu17Ni83(100) have been calculated by a semiempirical procedure based upon previously published data. These profiles indicate that surface enrichment of copper is not limited only to the topmost layer but occurs for several layers away from the surface as well. A comparison of the calculated segregation profiles based upon the experimental results for the (100) and (111) surfaces of Cu17Ni83 do not agree with predictions based upon thermodynamic models of segregation.


Surface-Wave-Induced Interference Effects In Angle-Resolved Photoemission, Peter A. Dowben, D. Heskett, E.W. Plummer, Y. Sakisaka, T.N. Rhodin, Cyrus Umrigar Oct 1984

Surface-Wave-Induced Interference Effects In Angle-Resolved Photoemission, Peter A. Dowben, D. Heskett, E.W. Plummer, Y. Sakisaka, T.N. Rhodin, Cyrus Umrigar

Peter Dowben Publications

New features are observed in normal-emission photoelectron spectra from Ni(100) in a narrow range of photon energies around 25 eV. These features are inconsistent with either direct transitions from the bulk or emission from occupied surface states or resonances. We suggest that they are a consequence of interference between the ordinary direct transition emitting an electron in the normal direction and the excitation from the same initial state into a final state that would normally be emitted from the surface at Γ― in the second surface Brillouin zone, but at this energy is trapped in a surface wave.