Molecular dynamics simulation of the physicochemical properties of silicon nanoparticles containing 73 atoms

The physicochemical properties of 73-atom silicon nanoparticles that have a crystal structure, a random atomic packing, and a packing formed by inserting a 13-atom icosahedron into a 60-atom fullerene are investigated using the molecular dynamics method. Analysis of the behavior of the internal energy, the radial distribution function, the distribution of bond angles, and the specific heat at a constant pressure C (p) in the temperature range 10-1710 K indicates that a crystalline nanoparticle undergoes melting at a temperature of 710 K and that the structural transformations occurring in particles with an irregular atomic packing exhibit specific features. It is demonstrated that the temperature dependence of the self-diffusion coefficient follows a linear behavior. Local deviations from the linear behavior are most pronounced for the crystalline nanoparticle.