Interpretation of potential transients during aluminum etch tunnel growth in the presence of sulfuric acid

Citation
J. Choi et al., Interpretation of potential transients during aluminum etch tunnel growth in the presence of sulfuric acid, ELECTROCH, 69(11), 2001, pp. 843-847
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics","Chemical Engineering
Journal title
ELECTROCHEMISTRY
ISSN journal
1344-3542 → ACNP
Volume
69
Issue
11
Year of publication
2001
Pages
843 - 847
Database
ISI
SICI code
1344-3542(200111)69:11<843:IOPTDA>2.0.ZU;2-W
Abstract
When sulfuric acid is added in an etching solution of 1 M hydrochloric acid , the effect of the sulfate ions on the aluminum etch pit formation and tun nel growth was investigated with the morphology study and current interrupt ions in applied etching current. Initial potential transient supports that sulfate ion works as a film forming agent and inhibits the pit initiation d uring the anodic current etching. Observation of ruptured oxide films sugge sts that cathodic hydrogen evolution can take place inside the pits. Curren t step reduction and cathodic pulse superimposition experiments indicate th at the actively dissolving tunnel tip surface is covered with aluminum chlo ride salts and sulfate ion moves far behind inside tunnels during the tunne l growth.