Evaluation of the Surface Energy of the Ternary Pt–Pd–Ni Nanoalloy

The surface energy of the ternary Pt–Pd–Ni nanoalloy was estimated. Ternary Pt500Pd500Ni250 nanoparticles of about 3 nm in size were formed in a molecular dynamics experiment using successive processes of quenching (rapid cooling at rates of 1 and 2 K/ps) of nanodroplets with an initial uniform distribution of components and annealing (relaxation) at final specified temperatures of 200, 700, and 1700 K. The simulation was carried out by the molecular dynamics method in the open LAMMPS program using various parameterizations of the interatomic interaction (parameterization of the tight-binding potential and two different parameterizations of the embedded atom potential). It was found that the value of the surface energy is sensitive both to the process of identification of surface atoms and to the conditions of the computer experiment (temperature, rate of thermally induced action, choice of the force field). The obtained patterns of change in surface energy, which determines the stability of the nanoparticle structure, can be explained by specific patterns of surface segregation, which depends on the choice of the force field.