Molecular dynamics study on structure stability, lattice variation, and melting behavior of silver nanoparticles

摘要

Molecular dynamics simulation is used to comparatively investigate the structure stability, lattice variation, and surface energy of Ag nanoparticles. It is revealed that the most stable structure of shapes transformed from an octahedron to a cuboctahedron with the cluster size increasing, and the energetically larger lattice contraction of particles should have higher surface energy. Simulation also shows that the cubic shapes have contributed highly to the lattice contractions of particles, and the lattice constants of octahedral shapes are the nearest to bulk Ag. In addition, a systematic work on the melting behavior of polyhedral shapes is carried out by shape factor, and the surface energy-dependent shape evolution of Ag particles is revealed. The present results agree well with experimental observations in the literature, and provide a deep understanding of the different physical and chemical properties of Ag nanoparticles.