Growth morphologies of crystal surfaces

摘要: We have expanded our earlier Monte Carlo model [Phys. Rev. A 38, 2447 (1988); J. Crystal Growth 100, 313 (1990)] to three dimensions and included reevaporation after accommodation growth on dislocation-induced steps. found again that, for a given set of parameters, the critical size, beyond which crystal cannot retain its macroscopically faceted shape, scales linearly with mean free path in vapor. However, three-dimensional (3D) systems show increased shape stability compared corresponding 2D cases. Extrapolation results mean-free-path conditions used morphological experiments leads order-of-magnitude agreement predicted size experimental findings. The region smooth (faceted) surfaces parameter space temperature supersaturation depends both surface bulk diffusion. While diffusion is seen morphology scale length, always destabilizing.The atomic roughness increases increase supersaturation. That is, tendency kinetics anisotropies stabilize reduced through thermal kinetic roughening. It also that solid-on-solid assumption, can be advantageously at low temperatures supersaturations, insufficient describe dynamics atomically rough interfaces where governs process. For an emerging screw dislocation, we find spiral mechanism dominates supersaturations. polygonization decreases increasing or When nutrient comparable lattice constant, combined effect reduces terrace width center region. At elevated nucleation-controlled dominate corner edge regions facet, while mode prevails center. Thus, addition confirming observation growing prevailing mechanism, are able obtain detailed insight into processes leading loss face facet stability.