Ultrathin films of lead oxide on gold: Dependence of stoichiometry, stability and thickness on O2 pressure and annealing temperature

摘要: Abstract Ultrathin oxide films grown in vacuum are important many industrial areas, including microelectronics and heterogeneous catalysis. In this paper, the dependence of stoichiometry, growth kinetics, thickness stability on O 2 pressure annealing temperature explored using a high-stability quartz-crystal microbalance Auger spectroscopy, for oxidation lead gold as model system. The increases abruptly at specific values pressure, explained previously Gibbs free energies. A qualitative difference is found between lead-oxide which 1 monolayer thick those or more monolayers thick; former apparently involve exclusively chemisorbed oxygen can be oxidized reduced reversibly thermal oxidation/annealing cycles, whereas latter an extended oxide, thermally stable, have smaller electron inelastic mean path. Accurate sticking probability obtained.