Monte Carlo simulations and experimental observations of templated grain growth in thin platinum films

Monte Carlo (MC) simulations were used to model microstructural evolution in Pt thin films with epitaxial seed grains buried in a polycrystalline matrix. The key to achieving purely epitaxial films via templated grain growth in such materials is the lateral coalescence of the seeds into a single epitaxial grain. The primary factors in determining whether this event takes place, for a given set of interfacial mobility/energy functions, are the relative initial sizes of the seed grains and polycrystalline matrix grains, and the initial degree of surface coverage of the epitaxial seeds. These characteristics are evaluated by varying the films’ initial microstructural parameters, including seed grain size, seed number density, seed surface coverage and polycrystalline matrix grain size. Additional simulations were carried out to investigate the effect of varying the energy and the mobility of seed–matrix interfaces. The critical values of seed–matrix grain size depend on the energy/mobility used, though seed coalescence remains the key criterion for epitaxial grain growth.