Molecular-dynamics investigation of early film growth of Pt/Au(100) and Au/Pt(100) and an interdiffusive growth mode

We simulate the early vapor deposition of Pt on reconstructed Au(100), and also Au on reconstructed Pt(100), with surface-embedded-atom-method potentials and the molecular-dynamics code DAMSEL utilizing simulated annealing. The early growth of Pt/Au(100) exhibits a type of interdiffusive growth where the Pt burrows into the Au substrate, forming a bumpy, mounded surface. The predicted growth is a consequence of the pliable nature of the reconstructed Au(100) substrate, and the ease with which it accommodates interlayer replacement diffusion. For Au/Pt(100), in agreement with low-energy electron-diffraction analyses, Au loses its quasihexagonal reconstruction at about 0.5-ML coverage, whereupon it grows layer by layer on Pt(100), pseudomorphic with the Pt(100) bulklike substrate, until a quasihexagonal reconstruction reappears at 2 ML.