In situ Grazing Incidence X-ray Diffraction Study of Electrochemically Deposited Pb Monolayer on Ag(111)

摘要

We report here the first in-situ X-ray diffraction measurements from a monolayer adsorbed at a metal-liquid interface. Diffraction peaks were observed from a monolayer of lead electrochemically deposited onto a silver (111) surface immersed in aqueous electrolyte. Grazing incidence geometry was used. The lead was found to order into a closed packed hexagonal structure, compressed 1.2% from bulk lead. The first order diffraction peak was 0.037 A(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.