Atomic insight into the solidification of Cu melt confined in graphene nanoslits

Molecular dynamics simulations are performed to study the solidification process of Cu melt in confined nanoslits (NSs) constructed by graphene sheets. Results shows the interactive influence of the nanoslits size and cooling rate on the solidification of confined Cu melt. With the increase of nanoslits size, the stable solidified structure will change from the initial {1 0 0}-oriented to {1 1 1}-oriented. It is found that increase of the cooling rate can promote this structural evolution. Besides, effect of cooling rate on the solidified structures of Cu melts deeply depends on the nanoslits size. At the cooling rate of 10 K/ps, 26 A may be the optimal size of the nanoslits to obtain the most ordered crystal structure. With further increase of the cooling rate, decrease of the size will obviously weaken the effect on the solidified structure and enhance the order degree of atomic arrangement. Our findings provide new evidence on the fabrication of controlled nanostructures by means of nanocasting in metal.