The critical layer number of Stranski-Krastanov growth mode epitaxial growth for bcc metallic thin films

摘要

Based on the classical elastic theory and a thermodynamic model for surface energy, the critical layer number n_c of Stranski-Krastanov growth mode epitaxial growth for bcc metallic thin films is calculated. n_c is determined by the consideration that the sum of the surface energy of a film and the lattice mismatch elastic energy between a substrate and the film is equal to the surface energy of the substrate. When the film layer number n is larger than n_c, a flat growth of the film on the substrate will transform to an island growth. Our predictions on several metallic films are in agreement with experimental results.