Time-resolved surface differential diffraction study of Ag electrodeposition on Au(111) and the role of surface stress

An in situ X-ray diffraction investigation using surface differential diffr action (SDD) was carried out to study the mechanism and kinetics of Ag elec trodeposition on Au(111). The effect of the surface stress on SDD measureme nts employing a thin film electrode has been investigated, which reveals th at stress-induced peak shifts can account for some inconsistency in previou s SDD results. Potential dynamic and potential step modes of deposition wer e used and the adlayer spacing of Ag on Au(111) was determined as a functio n of potential and time, respectively. A structural change in adlayer spaci ng during Ag electrodeposition on Au(111) was observed in both modes of dep osition, which is consistent with a transition from initial adsorption in a mixture of bridge and atop sites to three-fold hollow sites.