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The results of molecular dynamics simulation of the process of atom-by-atom growth of palladium nanoparticles are presented. The structures obtained for the Pdn clusters agree well with the results of the first-principles calculations. The low-symmetry atomic configurations for the structure of the Pd4 and Pd13 clusters have been obtained using the semiempirical potentials of the interatomic interaction for the first time.

This paper reports on the results of the molecular dynamics simulation of isothermal and isochronous annealings of binary clusters in the Cu-Ni and Cu-Pd systems. The specific features of the formation of the structure are investigated as a function of the component ratio and the cluster size. It is revealed that the Cu-Ni and Cu-Pd clusters have low and high tendencies toward amorphization, respectively. This is explained by different ratios between the atomic sizes in compositionally ordered systems.

The structure of an fcc(001)/fcc(001) interphase boundary in a “nickel hemispherical crystal nanoparticle-palladium crystal substrate” system is investigated using molecular dynamics simulation with multiparticle potentials calculated in the framework of the embedded-atom method as a function of the angle of rotation of the nanoparticle. Relaxation transformations are found to occur in a component of the system under investigation with a larger lattice parameter. It is demonstrated that, under given annealing conditions, the system is characterized by a size dependence of the angle of rotation of a nanoparticle: the annealing leaves the location of large islands virtually unchanged but brings about a rotation of small nanoparticles into a parallel orientation or an orientation with a local energy minimum.

An isothermal kinetic diagram for the beginning of homogeneous nucleation is constructed using the molecular-dynamics model of an instantaneously supercooled iron melt near the icosahedral percolation transition temperature identified with the glass transition temperature T g . This diagram is compared with the theoretical one calculated using quantitative information obtained by analyzing the kinetics of the initial stage of growth of supercritical nuclei at temperatures higher than T g . A satisfactory coincidence of the theoretical curve with computer simulation data at temperatures higher than T g and substantial disagreement with these data below T g , where crystallization is necessarily preceded by the formation of an icosahedral percolation cluster, demonstrate the substantive influence of an icosahedral substructure on the nucleation rate predicted by the classical theory.

The atomic mechanisms and kinetics of self-diffusion of Pd adatoms on a single-crystal Pd(001) surface are investigated using molecular dynamics simulation. It is shown that the migration of Pd adatoms on the Pd(001) surface predominantly occurs through the relay-race mechanism with the participation of substrate atoms. The activation energy for an elementary event of relay-race self-diffusion is calculated from the kinetic equation describing the change in the concentration of surface adatoms labeled at the initial instant of time.

It is shown that a system of classical particles considered in a molecular dynamics model with Pak-Doyama pairwise interatomic potential adequately describes not only the various structural states of iron (melt, bcc crystal, metal glass) but also the complex self-organization processes occurring in first-and second-order phase transitions (crystallization and vitrification, respectively). When the temperature is varied at a constant rate of 6.6×1011 K/s, crystallization sets in from both the amorphous and the liquid state; at a rate of 1.9×1012 K/s, crystallization is observed only in the amorphous state; and when heated at a rate of 4.4×1012 K/s, the model amorphous iron transfers to the liquid state without crystallization. The energy of homogeneous formation of a crystal nucleus in the bulk of the amorphous phase of iron is calculated to be ∼0.71 eV under the assumption that there is a spectrum of activation energies.