SURFACE ORDERED PHASES OF AG ON THE MO(110) SURFACE BY RHEED OBSERVATION

Surface ordered structures of Ag deposited on a Mo(110) surface have been studied by RHEED. Room temperature condensation of Ag on the Mo surface exhibits a Frank-van der Merwe growth mode. However, with high temperature condensation above 400-degrees-C a two-dimensional Ag(111) epitaxial layer with the Kurdjumov-Sachs orientation relationship appears at one monolayer deposition. Elevating the temperature of the film deposited with one monolayer several surface ordered phases appear. At 650-degrees-C, the surface structure changes from the Ag(111) layer to [2/0 1/9BAR] structure, and at 700-degrees-C it changes to a 2 X 2 structure. At 750-degrees-C, the 2 X 2 structure vanishes to yield a 1 X 1 structure of the clean Mo surface. Continuing deposition of Ag on the Mo surface kept at temperature between 400-degrees-C to 600-degrees-C, the Ag(111) layer is completed at one monolayer deposition, followed by Ag island growth, showing that the growth of Ag takes place in accordance with the Stranski-Krastanov growth mode.