In this study, we present Cu L3M45M45 Auger spectra in coincidence with Cu 2p3/2 from the oxidized surface of Cu (i.e. CuOx/Cu) and Cu 2p3/2 lines in coincidence with Auger 1G and 3F terms of Cu L3VV from Cu. Comparison of the L3VV line structures of CuOx/Cu with that of Cu reveals that the Auger line has changed to band‐like in the CuOx/Cu material. The reduced mean free path of the Auger electron in coincidence with the photoelectron displays the Auger line of the CuOx surface. The asymmetric broadening of the Cu 2p3/2 lines in coincidence with 1G and 3F terms from Cu illustrates that a single‐step model is essential for describing the Auger lineshape of copper. Copyright © 2001 John Wiley & Sons, Ltd.

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The gold(110) single crystal exhibits a (1 × 2) surface structure when clean, but when immersed in 0.01 M HClO 4 under potential control the structure has been found to change. Throughout the double-layer region the structure remains as .1 × 2/ but when the potential is increased above 0.9-1.0 V vs. Ag/AgCl (the preoxidation region) the surface structure changes to a centred rectangular structure. This structure forms reproducibly but has limited stability. After the initial oxidation, the structure prevails until 1.2-1.3 V, whereupon oxidation occurs on a larger scale and the surface structure becomes .1 × 1/. These structures return to .1 × 2/ after reduction of the oxide, proving that the structural changes are reversible. X-ray photoelectron spectroscopy of these regions has shown a difference in the chemical state of the oxygen. Adsorbed perchlorate ion is initially the only oxygen component but as the potential increases the peak shifts into the hydroxide region and finally splits into a hydroxide peak and a metal oxide peak. This study indicates a new way of looking at the structure and composition of the gold surface and provides insight into the nature of the interaction between the surface and the solution.

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The electrochemical underpotential deposition (UPD) of lead on Au(110) was investigated by XPS using a custom-built ultrahigh vacuum apparatus containing a chamber for electrochemical studies. A two-step deposition process for lead UPD was confirmed. A large increase in the surface concentration of oxygen was found in solutions containing lead. The presence of lead was detected on the gold surface at all potentials within the range investigated (−500 mV to 1500 mV vs. Ag/AgCl). Degradation of chlorine by x-rays was observed. The change in surface components with potential was investigated and linked to models of UPD and oxidation. The initial random deposition of lead from solution led to surface disordering.