Abstract

The surface specificity of second harmonic generation (SHG) has been used to monitor, we believe for the first time in situ, the transformation from the (1 × 1) to the (1 × 23) reconstruction of an Au (111) crystal. As shown in Fig. 1, SHG measurements were made in reflection under a 45° angle of incidence. The As laser light source served the fundamental output of a Nd;YAG laser, delivering 10-mJ pulses of 10-ns duration, which were slightly focused to 1 mm² onto the single crystal Au electrode within an electrochemical cell. The Au electrode was a disk ~4 mm in diameter. The As electrolyte served an aqueous solution of 0.01-M H₂SO₄. Further details of the optical arrangement were published elsewhere.¹

© 1990 Optical Society of America