Fractal Pattern Growth in Ti—Implanted Steel with High Ion Flux

We report on the formation of metal nanometre phase and fractal patterns in steel using metal vapour vacuum arc source in implantation with high ion flux.The dense nanometre phases are cylindrical and well dispersed in the Ti-implanted layer with an ion flux up to 50μA/cm^2.The collision fractal pattern is formed in Ti-implanted steel with an ion flux of 25μA/cm^2 and the disconnected fractal pattern is observed with an ion flux of 50μA/cm^2.The average density of nanometre phases decreases from 1.2×10^11/cm^2 to 6.5×10^10/cm^2 as the ion flux increases from 25μA/cm^2 to 50μA/cm^2.Fractal pattern growth is in remarkable agreement with Sander's diffusion-limited aggregation model.The alloy clusters have diffused and aggregated in chains froming branches to grow a beautiful tree during Ti implantation with an ion flux ranging from 75μA/cm^2 to 85μA/cm^2.We discuss the model of fractal pattern growth during ion implantation with high ion flux.