In Situ Scanning Tunneling Microscopy of Corrosion of Silver-Gold Alloys

Abstract

An in situ scanning tunneling microscope (STM) was used to observe the morphological changes accompanying the selective dissolution of Ag h m low-Ag content Ag-Au alloys in dilute perchloric acid This study was undertaken to explore the role of surface diffusion in alloy corrosion pmcesses. These d t s are interpreted within the h e w o r k of the kink-ledge-terrace model of a aystal surface and a recent model of alloy corrosion based on a variant of percolation theory. The corrosion process leads to roughenhg of the surface by dissolution of Ag atoms h m terrace sites. h e a l i n g or smootheniug of the surface occurs by vacancy migration through dusters and the subsequent annihilation of dusters at terrace ledges.

Synergism between rare earth cerium(IV) ion and vanillin on the corrosion of steel in H2SO4 solution: Weight loss, electrochemical, UV–vis, FTIR, XPS, and AFM approaches

“…The atomic force microscope provides a powerful means of characterizing the microstructure [51][52][53][54]. The two-dimensional AFM images of CRS surface in 1.0 M H 2 SO 4 are shown in Fig.…”

Coarsening Mechanisms in a Metal Film: From Cluster Diffusion to Vacancy Ripening

“…While CD was recognized in older studies of coarsening of 3D metal (adatom) clusters on nonmetallic surfaces [11,12], it has been overlooked in 2D metal-on-metal systems, presumably because of an expectation that diffusion of large 2D adatom or vacancy clusters is insignificant. Previously, the coarsening of vacancy islands has received only cursory attention [13,14]. We find, in fact, that CD of adatom islands dominates coarsening for low u, and present detailed modeling of this behavior.…”

Nanoporous Gold Leaf: “Ancient Technology”/Advanced Material

“…[15,16] The reason for this may lie in the historical focus of dealloying as a corrosion process Ð dealloying of stainless steels and brasses may lead to stress corrosion cracking and undesirable materials failure. [17,18] A second reason may be that the use of gold alloys is often expensive. In our research, we have been looking for highly porous and highly conductive large-area electrodes for use in electrocatalysis.…”