Surface X-ray Scattering Measurements of the Substrate Induced Spatial Modulationof an Incommensurate Adsorbed Monolayer

摘要

We report in-situ surface X-ray scattering measurements of electrochemicallydeposited Ti monolayers on Ag(III). We find that the Ti adlayer forms an incommensurate, two dimensional solid and we determine the spatial modulation in the Ti monolayer that is induced by the periodic potential of the substrate. The modulation of the Ti monolayer changes the intensity of the X-ray scattering from the Ag substrate (the Ag crystal truncation rods), since the modulation wavevectors are commensurate with the substrate periodicity. By measuring the intensity changes along the Ag truncation rods, we determined the first Fourier component of the longitudinal part of the substrate induced modulation to be 0.03 angstroms, and the spacing of the Ti monolayer above the Ag surface to be 3.05 angstroms.