LOW-ENERGY ELECTRON-DIFFRACTION STUDIES OF INTERACTION OF OXYGEN WITH A MOLYBDENUM (100) SURFACE

Oxygen adsorption on the (100) surface of molybdenum single crystals was examined by low-energy electron-diffraction (LEED) in a display-type apparatus. Continuous diffraction-pattern observations from an initially clean surface were made at reaction temperatures between room temperature and 850°C. Below 650°C, no new ordered structures were observed. At 750°C, four ordered structures were formed on the surface with increasing oxygen coverage. The thermal characteristics and kinetics of formation of these oxides are discussed. In addition, models of surface structure with less than a monolayer oxygen coverage are presented.