Formation of regular polyicosahedral and defected crystalline structures in growing Lennard-Jones clusters

•Growth of nearly 500 LJ clusters of size from N=13 up to 9800 was simulated.•Formation of better ordered clusters is facilitated at higher growth temperatures.•Kinetic effects determine the structure formation of large growing LJ clusters.•New dense-packed layers in layered fcc/hcp clusters are formed by island growth.•Decahedral and tetrahedral fcc clusters evolve to regular polyicosahedral structure.

Formation of solid structure and its subsequent enlargement have been analysed in simulated growth of Lennard-Jones (LJ) clusters from vapour. Four series of the Monte Carlo simulations, carried out for constant temperature T⁎=0.25, 0.30, 0.35 and 0.40 in reduced units, were started from LJ13 icosahedral cluster used as a seed in a supersaturated LJ vapour. In the first simulation stage, all the 504 simulated clusters (over 100 growth runs for every analysed temperature) achieved the size N≈1000N≈1000. Structural analysis and visualisation showed that at this size many of the obtained clusters (i.e. 10%, 29%, 34% and 66%, respectively, for the above temperatures) were well ordered. They were found to have regular internal structure mainly of regular polyicosahedral and layered fcc/hcp structure. In the second simulation stage practically all the obtained clusters were grown until N=3300 was reached, while in the third stage the selected regular structures attain N  =9800. Visualisation of the internal structure of the growing regular clusters from their solidification up to the final size N≈9800N≈9800 revealed that (i) the layered fcc/hcp structure maintains layered character if fcc layers are relatively thin, and (ii) r-PIC clusters initially keep the structure during the growth, but its subsequent growth leads to the formation of disordered regions.