Mechanistic Studies on Room Temperature Photoexcitation Effects on Passivity Breakdown of Ultrathin Surface Oxide Films Formed on Ternary Al-5%Cu-5%Ni Alloys

September 23, 2010

Journal Article

Mechanistic Studies on Room Temperature Photoexcitation Effects on Passivity Breakdown of Ultrathin Surface Oxide Films Formed on Ternary Al-5%Cu-5%Ni Alloys

Abstract

How the composition of nanoscale surface oxides formed on complex metal alloys affects their passive state is a problem of great interest both from scientific and technological perspectives. In this work, we report on experimental studies regarding the problem concerning the role of room temperature photo-excitation on altering composition of ultra-thin oxides formed on ternary Al-Cu-Ni thin film alloy surface and its influence in passivity breakdown in aqueous media. Extensive studies have been carried out on pure copper, Al-5%Cu and Al-5%Cu-5%Ni alloy thin films to investigate mechanistic role of alloying elements as well as their oxide formation characteristics on the resulting passive state. The differences in nanoscale oxide composition formed has a remarkable influence on the passivity breakdown of the oxide films as verified from electrochemical measurements and possible mechanisms leading to the observations are discussed in detail.

Revised: May 9, 2011 | Published: September 23, 2010

Citation

Chang C., M.H. Engelhard, and S. Ramanathan. 2010. Mechanistic Studies on Room Temperature Photoexcitation Effects on Passivity Breakdown of Ultrathin Surface Oxide Films Formed on Ternary Al-5%Cu-5%Ni Alloys. Journal of Physical Chemistry C 114, no. 41:17788–17795. PNNL-SA-73928. doi:10.1021/jp106297c