TY  - JOUR
AU  - Garcia, S. G.
AU  - Salinas, D. R.
AU  - Staikov, G.
TI  - Underpotential Deposition of Cd on Ag(111): An in situ STM study
JO  - Surface science
VL  - 576
SN  - 0039-6028
CY  - Amsterdam
PB  - Elsevier
M1  - PreJuSER-38552
SP  - 9 - 18
PY  - 2005
N1  - Record converted from VDB: 12.11.2012
AB  - The kinetics and mechanism of Cd underpotential deposition (UPD) and involved surface alloy formation processes the system Ag(1 1 1)/Cd2+,SO42- are studied by means of combined electrochemical measurements and in situ scanning tunneling microscopy (STM). The results show that the UPD process starts with a formation of an expanded (diluted) adlayer with a superlattice structure Ag(1 1 1)-(root3- x root19)R23.4degrees. In the underpotential range 50 mV < DeltaE < 80 mV this adlayer transforms to a condensed close packed Cd monolayer via a first order phase transition. At long polarization times the condensed monolayer undergoes structural changes involving place exchange processes between Cd atoms and surface Ag atoms. A formation of a second Cd monolayer and a significant Ag-Cd surface alloying take place at lower underpotentials (DeltaE < 50 mV). The kinetics of surface alloying are analyzed on the basis of a recently proposed diffusion model including a relatively fast initial formation of a very thin surface alloy film and a subsequent slow alloy growth controlled by solid state diffusion. The anodic dealloying results in an appearance of monatornically deep pits, which disappear quickly at relatively high underpotentials (DeltaE > 550 mV) indicating a high mobility of surface Ag atoms. (C) 2004 Elsevier B.V. All rights reserved.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000226872600004
DO  - DOI:10.1016/j.susc.2004.11.037
UR  - https://juser.fz-juelich.de/record/38552
ER  -