扩散系数局域变化对生长亚单层薄膜的影响

EFFECT OF LOCAL DIFFUSION COEFFICIENT VARIATION ON SUBMONOLAYER GROWTH

将Ａｕ沉积在ＰＶＦ有机膜基底上生成亚单层薄膜，发现了不同于金属／单晶组合的亚单层表面形貌，即某些表面区域形成特别大的团簇，而团簇周围有一近似圆形空带．推测这是由于表面局部区域扩散系数发生变化引起的，用改进后包括边缘扩散的ＤＤＡ模型证明了这一推测．模拟的结果还表明在ＰＶＦ膜基底上。

Abstract In this article Au was deposited on PVF(Polyviny formal) film which was kept at 253K to grow Au submonolayer film.It is found that there are special areas whose morphology differs from other's experiment in which metal was deposited on single crystal.In these areas especially big clusters were found and they were surrounded by empty bands.Our deduction that this is caused by variation of local coefficient is proved by a modified DDA(Deposition Diffusion Aggregation) model which includes edge diffusion.We also argue that the relationship between cluster diffusion coefficient D S ,and particles numbers S which the cluster contains should be exponential for Au cluster on PVF film instead of power dependent in original DDA model.