Monte Carlo simulation of ramified aggregates on hetero-substrates

We have studied the aggregation of particles on a hetero-substrate consisting of two different substrates A and B with finite surface barriers E_\rm AB and E_\rm BA between the AB and BA boundaries, respectively. With the diffusion energy limited aggregation (DELA) model, we find that the number of clusters and the mean radius of gyration of the clusters are dependent on the surface barriers E_\rm AB and E_\rm BA. For the case with a constant of E_\rm BA, a series of minima are summarized as E_\rm AB = (E_0 - k_\rm BA E_\rm BA )/ k_\rm AB with k_\rm AB and k_\rm BA being two integers, for main minima (k_\rm BA=k_\rm AB- 1) and two local minima (k_\rm BA=k_\rm AB and k_\rm BA=k_\rm AB + 1) between two neighbouring main minima.