STRUCTURAL PERFECTION IN PHYSISORBED FILMS - A SYNCHROTRON X-RAY-DIFFRACTION STUDY OF XENON ADSORBED ON THE AG(111) SURFACE

Synchrotron x-ray scattering has been used to investigate the structur e and growth of xenon films physisorbed on the Ag(111) surface. For gr owth under quasiequilibrium conditions, the bulk Xe-Xe spacing is reac hed;at monolayer completion and fcc films of thickness greater-than-or -equal-to 220 angstrom are observed. Under kinetic growth conditions, intensity oscillations in the specular reflectivity as a function of t ime demonstrate nearly layer-by-layer growth. Modeling of the intensit y at a fixed coverage allows profiling of the Xe/vacuum interface as w ell as a direct determination of the film's thickness and layer spacin gs.