AVS 49th International Symposium
    Electrochemistry and Fluid-Solid Interfaces Tuesday Sessions
       Session EC-TuP

Paper EC-TuP1
A Potentiodynamic Study of the Influence of Chloride and Chromate on Passive Films on Copper

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Poster Session
Presenter: M.A. Hossain, Lamar University
Authors: M.A. Hossain, Lamar University
M.Y.A. Mollah, Lamar University
D.E. Mencer, Wilkes University
R. Schennach, Technical University of Graz, Austria
H. McWhinney, Prairie View A&M University
D.L. Cocke, Lamar University
Correspondent: Click to Email
Copper is being increasingly studied today because of its use for electronic interconnects, its resistance to corrosion and its structural and alloying properties even though it undergoes pitting corrosion in the presence of aggressive ions including chloride and bromide. In a research program to delineate the physical and chemical processes that control metal and alloy oxidation, we have found it necessary to explore in detail the oxidation of copper. Although the electrochemical oxidation of copper has been much studied, there is a need to examine the nature of the oxidation product films developed in the process in light of recent discoveries of the importance of the intermediate oxide, Cu@sub 3@O@sub 2@. In this study, the electrochemical oxidation of copper is examined in neutral solution by cyclic voltammetry and linear sweep voltammetry. The influences of chloride and chromate ions have been investigated. Chloride has been found to strongly influence the passive film and to produce additional chemical species in the product films. Chromate influences the electrochemical properties of the passive films by increasing resistance to corrosion and increasing resistance to electrochemical reduction during linear sweep voltammetry. The structural and chemical influences have been examined by SEM and XPS. The chemical and structural changes in the product films will be discussed in terms of the increasing body of information being determined on the nature of oxidation produced films on copper by thermal, electrochemical and plasma means.