An investigation into the melting of silicon nanoclusters using molecular dynamics simulations

Using the Stillinger-Weber (SW) potential model, we have performed molecular dynamics (MD) simulations to investigate the melting of silicon nanoclusters comprising a maximum of 9041 atoms. This study investigates the size, surface energy and root mean square displacement (RMSD) characteristics of the silicon nanoclusters as they undergo a heating process. The numerical results reveal that an intermediate nanocrystal regime exists for clusters with more than 357 atoms. Within this regime, a linear relationship exists between the cluster size and its melting temperature. It is found that melting of the silicon nanoclusters commences at the surface and that T(m,N) = T(m,Bulk)-αN(-1/3). Therefore, the extrapolated melting temperature of the bulk with a surface decreases from T(m,Bulk) = 1821 K to a value of T(m,357) = 1380 K at the lower limit of the intermediate nanocrystal regime.