Fig. 5

Growth of three aggregates calculated with the extended DLA model. The square lattice is made of 256 * 256 sites and contains three nucleation seeds (single sites at the beginning of the simulation). The number of surface-diffusion steps is 20. a Monomers are inserted far away from the growing structures. Blue arrows highlight the growth directions of the NPs. b Monomers randomly appear inside the bright area with a radius of 110 lattice spacings. There is no preferential growth direction. The green-to-red color scale indicates the time at which aggregation occurred: the oldest aggregation events appear in green and the most recent in red