Structural analysis of Ni nanoparticles in thermal cooling by molecular dynamics

The Sutton–Chen potential was used to simulate the process of solidification of Ni nanoparticles at temperatures ranging from 1000 to 100 K in the cooling process. The number of atoms per particle ranged from 500 to 4000. The results show an expected increase in solidification temperature with size. Analysis of the first-neighbour interatomic distance as a function of temperature showed exponential behaviour up to the phase transition. A reduction in the interatomic distance was observed at small sizes below the established lattice parameter. Characterization of the surface as a function of the number of first neighbours allowed interpretation and quantification of the surface planes as a function of particle size at low temperatures.