薄膜生长的元胞自动机模型

在一定条件下，单个原子或原子团簇在液体基底表面无规律扩散和凝聚，并形成具有分形结构的分枝状凝聚体，形成此类凝聚体所需的时间非常短(约1—10s)，直接观察原子或原子团簇在液体表面的成核、扩散及凝聚过程十分困难。元胞自动机是研究复杂体系的一种理想化模型，特别适合那些难以用数学定量描述的复杂动态体系实施计算机模拟。针对在液体基底表面的金属原子会凝聚形成具有特殊结构的分形凝聚体这一实验结果，建立了团簇一团簇凝聚的元胞自动机模型，对此类液体基底表面的金属原子分枝状凝聚体的生长过程进行了计算机模拟。模拟结果表明，凝聚体的分形维数和回旋半径都与实验结果相一致，为研究薄膜生长机理提供了一种新的方法。

Cellular Automata Model of Thin Film Growth

Depending on practical conditions ,both single atoms and atomic clusters can randomly diffuse and aggregate on liquid substrates ,which may result in ramified aggregates with different structures .Generally ,it is difficult in experiment to observe nucleation ,diffusion and aggregation processes of single atoms and atomic clusters on liquid substrates directly since the aggregation time intervals on liquid substrates are very short(about 1-10s).Cellular Automata is an ideal model of complex system ,which is especially advantageous for modeling complex dynamic system which is difficult to be processed in mathematics and is very easy to implement in computer simulation .Based on the experimental observation , a cellular automata model on cluster-cluster aggregation is established and the growth mechanism of the metal aggregates is simulated .The computer simulation results show that not only the fractal dimension but also the radius of gyration of the aggregates are in good agreement with the experimental findings. It provides a new method to study the growth mechanisms of thin films.