Proper transition rates in kinetic mean-field and Monte Carlo simulations of dynamic processes are very important to obtain realistic results. We show that by proper choice of the transition rates one can unify the advantages and eliminate the disadvantages of different models used in the literature [see, e.g., Senhaji et al., Surf. Sci. 274, 297 (1992) (kinetic tight binding Ising model), Martin, Phys. Rev. B 41, 2279 (1990) and Cserháti et al., Surf. Sci, 290, 345 (1993)]. Furthermore, we also show that this choice cannot be considered simply as an extension of the previous ones. It contains an additional parameter controlling the ratio of the transition rates in the bulk and close to the surface (Γsurf/Γbulk), which influences the kinetics of surface segregation. We show that some results obtained previously need reconsideration. We illustrate, e.g., how the composition dependence of the transition rates (diffusion coefficient) influences the 'surfactant formation and dissolution mode'. For example, the dissolution kinetics can deviate from the parabolic law on the nanoscale in accordance with our recent results [Erdélyi et al., Phys. Rev. B 69, 113407 (2004)]. Furthermore, we also present how the (Γsurf/ Γbulk) ratio affects the kinetic, segregation isotherm.
|Number of pages||6|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Dec 1 2004|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics