Author Type

Graduate Student

Date of Award

1995

Document Type

Thesis

Publication Status

Version of Record

Submission Date

October 2026

Thesis/Dissertation Advisor [Chair]

Jordan, Robin G.

Abstract

Angle-resolved UV photoelectron spectroscopy has been used to investigate some of the properties of the occupied Shockley-type surface states that exist on the (111) surfaces of Cu, Au, ordered Cu3Au and ordered CuAuI. These states appear in normal and off-normal spectra near the Fermi level and their binding energies are independent of photon energy; however, the intensity of their emission relative to that of the d-bands is photon energy dependent, decreasing monotonically from ArI to NeI to HeI. As the emission angle is increased from the normal, the states move towards and eventually cross the Fermi level, and we have measured this dispersion in k space. We show that the occupied extents of the dispersion relations, delta k, are related to features of the bulk band structures. For example, in Cu and Au the surface state follows the dispersion of the uppermost occupied band edge in the vicinity of the L-point and so the delta k extent is related to the (111) neck radius on the Fermi surface. Because the changes in the delta k extents are of the same order as the experimental uncertainty, we are unable to determine precisely how they vary with composition. We have fitted the dispersion data to 'free-electron' parabolas and calculated an effective electron mass in each case; we find that the effective masses in the alloys are somewhat larger than in the pure metals. The photoemission measurements described here on CuAuI(111) are the first ever to be taken on an alloy of that composition.

Extent

115 p.

Comments

Thesis (M.S.)--Florida Atlantic University, 1995.|Thesis (M.S.)--Florida Atlantic University, 1995.

Identifier

FADT15221

Format

pdf

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