Second harmonic generation spectroscopy of the potential induced surface reconstruction of the gold(110) electrode in perchloric acid electrolyte.

In-situ optical second harmonic generation (SHG) spectroscopy was used to examine the potential induced surface reconstruction of a Au (110) surface in a solution of 0.01 M HClO$\sb4.$ The SHG rotational anisotropy was measured at different potentials using the fundamental beam (1064 nm) of the Nd:YAG laser. Analysis of the data shows that the overall symmetry of the surface is C$\rm\sb{s}.$ It was also found that the second order nonlinear susceptibility for both the reconstructed and the unreconstructed surface have a large three fold symmetry component. We suggest that the three-fold symmetry source is partly due to the (111) microfacets that are present on the (110) surface