When N increased the diffusion started to agglomerate the Nps on well-defined lines leading to the formation of LSFL structures. In addition a decrease of Nps size from 56 to 7 nm is noticed. Different mechanisms of size reduction have been proposed in the literature but are still under discussion. In fact two main mechanisms have been suggested for the Nps size change: defragmentation phenomenon and size reduction through the heating–melting–evaporation