Study of crystal-amorphous phase transition and morphologies of metal nanoparticle Fe under annealing

Abstract

The present work investigates the crystal-amorphous phase transition and morphologies of metal nanoparticles Fe (NPs) using means of molecular dynamics (MD) simulation. Tracing the number of crystal atoms and the analysis of radial distribution functions, we found that the amorphous Fe NP is transformed into bcc crystal one when it was annealed for long times at 900 K. At the early stage of the annealing, small nuclei form in different places of NP and dissolve for short times. After long times some nuclei form and gather nearby which creates the stable clusters in the core of NP and to spread into the surface of NP. Based on the mean potential energy per atom analysis and MD data visualisation technique, the effect of B atoms that prevent the growth of crystallisation as well as the different morphologies of Fe and FeB NPs have been investigated in detail.