In-situ grazing incidence X-ray diffraction study of electrochemically deposited Pb monolayers on Ag(111)

We report here the first in situ X-ray diffraction measurements from a monolayer adsorbed at a metal/liquid interface (lead electrochemically deposited on silver (111)). The lead was found to order into a close-packed hexagonal structure, compressed 1.2% from bulk lead. The first order diffraction peak was 0.037 Å-1 broad in the radial and azimuthal directions, indicating that even in an aqueous environment the Pb monolayer forms a well-ordered two-dimensional solid. A rotational epitaxy angle (angle between the Pb and Ag surface lattices) of 4.4° was observed. © 1988.