The second-harmonic response of single-crystal silver electrodes obtained with an interference method Original Research Article

The second-harmonic response of several single-crystal silver electrodes is investigated at a long wavelength. In contrast to earlier experiments, the phase of the signal is obtained directly by an interference method. By comparing measurements at two different angles of incidence, the Rudnick-Stern coefficient characterizing the response perpendicular to the surface can be estimated; for Ag(100) and Ag(111) it agrees fairly well with calculations based on the jellium model. For the Ag(110) surface, the twofold amplitude depends on the electrode potential; in addition, a contribution with a three-fold symmetry is observed. These unexpected features are probably caused by a facetting of the Ag(110) surface.