NUMERICAL-SIMULATION OF PT OVERLAYERS ON NI(111) AND CO(0001)

The growth of pseudomorphic Pt layers (from one to four) on Ni(111) an d Co(0001) has been investigated by the ECT-BFS method. The behaviors on the two substrates are very similar. The growth of the first layer appears to be highly favorable as the energy of the system is negative . Higher coverages could be stabilized with huge relaxations perpendic ularly to the surface. The evolution of the plane by-plane energies (s eparated in stress and chemical contributions) and relaxations during the growth is presented and discussed. The always-stabilizing chemical interaction at the interface makes it likely that interdiffusion of m etals could be a competing mechanism.