MOLECULAR DYNAMICS STUDIES OF ULTRATHIN METALLIC FILMS GROWTH. A.E.Moroz, A.A.Katsnelson, O.S.Trushin, Department, of Solid State Physics, Moscow State University, Russia

We announce the results of our molecular dynamics (MD) simulation of the growth processes of metallic ultrathin films in molecular beam epitaxy procedures. In the case of the deposition of Co atoms to the Co(100) substrate we studied the homoepitaxy process. The Co/Co system was modelled at the substrate's temperature of 300 and 800 K. In both cases the atoms falling onto the substrate formed crystalline film and its structure was similar to the substrate's one. When the substrate's temperature was increased, the structure of the film was less ordered. The dynamics of the film growth was also observed. The Co atoms first formed two-dimensional islands on the surface and only later filled in the spaces between these groupings. We modelled the getero epitaxial process in the case of deposition of Ag atoms to the Co(100) substrate. The Ag atoms settled between the cobalt atoms and formed well-ordered structure. But if the Co atoms formed FCC plane lattice corresponding to the plane (100) then

Ag atoms formed FCC plane lattice corresponding to the plane (111). The system obtained was heated to 1500 K and cooled rapidly to 100 K. The two-dimensional pair correlation functions g(r) for Ag layers were calculated. Thier analysis indicates the absence of long-range correlations which are typical for well-ordered crystal layers. Whereas, the short-range order in the Ag film was detected. It corresponds to amorphous plane lattice appearance.