Surface alloy formation and two-dimensional vitrification in adsorbed monolayers on Molybdenum (112) surfaces

Low-energy electron diffraction, scanning tunneling microscopy, contact potential difference, and Auger electron spectroscopy methods are used to observe the formation of surface alloys during annealing of Dy, Gd, Sr, and Be monolayers adsorbed on Mo(112) surfaces. Surface alloys develop as a nanodispersed system of oligomeric clusters in the Dy and Sr films and as a continuous covering in the Be and Gd films. It is shown that Dy films, which form a Dy-Mo surface alloy on annealing, will enter a two-dimensional glassy state after cooling (quenching) to low temperatures, while the surface alloys of Be and Gd are formed in a crystalline state.