Analytic embedded-atom method (EAM) interatomic potentials for body-centered cubic (bcc) transition metals have been constructed. The total energy is regarded as consisting of a pair potential part, an embedding interaction part and a modification term. All these parts are analytic functions of the atomic separations only and are fitted to various bulk properties, such as cohesive energy, vacancy formation energy, lattice constant and elastic constants. The present potentials are shown to predict a more realistic pressure–volume relationship so that interactions at separations smaller than that of the first-nearest neighbors can be treated. Interstitial formation energies are calculated for various configurations, using quenched molecular dynamics. Vacancy, surface and phonon spectra have been also studied andsatisfactory agreement with available experimental data has been found.

Using molecular dynamics simulations with an analytical embedded-atom method (MAEAM) model, the diffusion behavior of helium atoms at two Σ=5 symmetric grain boundaries of Ni was investigated in the present paper. The simulations demonstrate that the interstitial helium atoms are stable at the grain boundaries. Helium atoms in Ni lattices could diffuse easily to the grain boundary and precipitate into a cluster, which confirmed the fact that helium atoms could nucleate and grow up into bubbles at the grain boundaries. The diffusion activation energy of interstitial helium atom at grain boundaries was also determined.

In the present paper, the surface and size effects on the alloying ability and phase stability of immiscible alloy nanoparticles have been studied with calculating the heats of formation of Au-Pt alloy nanoparticles from the single element nanoparticles of their constituents (Au and Pt) with a simple thermodynamic model and an analytic embedded atom method. The results indicated that, besides the similar compositional dependence of heat of formation as in bulk alloys, the heat of formation of alloy nanoparticles exhibits notable size-dependence, and there exists a competition between size effect and compositional effect on the heat of formation of immiscible system. Contrary to the positive heat of formation for bulkimmiscible alloys, a negative heat of formation may be obtained for the alloy nanoparticles with a small size or dilute solute component, which implies a promotion of the alloying ability and phase stability of immiscible system on a nanoscale. The surface segregation results in an extension of the size range of particles with a negative heat of formation. The molecular dynamics simulations have indicated that the structurally and compositionally homogeneous Au Pt nanoparticles tend to form a core-shell structure with temperature increasing.

In the present paper, the size and temperature effects on lattice distortion of Ag and Pt nanoparticles have been investigated in terms of atomic mean bond length using the molecular dynamics simulations and the modified analytic embedded atom method. It is found that the lattice contraction ratio decreases linearly with the reciprocal of the particle size. The average value of lattice contraction over the whole system is larger than that of the experimental data, and the average value of lattice contraction in the inner core has a better agreement with the experiment results. This phenomenon is mainly resulted by inhomogeneous lattice distortion. The surface distortion and the size effect on the inner core distortion are remarkable. As the grain size increases to a certain degree, the inhomogeneous surface lattice distortion is mainly localized to the outer shell with a thickness of 2-3 lattice parameters.

Molecular dynamics simulations incorporating an analytic embedded atom potential have been used to investigate the atomic structure and surface order of the Al vicinal surfaces for the temperature up to 900 K. The relaxation, mean square vibrational amplitude, and structure factor as a function of temperature, and of the terrace width for the p(100) (111) surfaces (2 p 10) are discussed. The obtained structure factor indicates that the anharmonic effect reduces with increasing terrace widths. The decrease of surface energy with increasing terrace width also supports this conclusion.