Abstract: A new interatomic potential for the pure tin (Sn) system is developed on the basis of the second-nearest-neighbor modified embedded-atom-method formalism. The potential parameters were optimized based on the force-matching method utilizing the density functional theory (DFT) database of energies and forces of atomic configurations under various conditions. The developed potential significantly improves the reproducibility of many fundamental physical properties compared to previously reported modified embedded-atom method (MEAM) potentials, especially properties of the β phase that is stable at the ambient condition. Subsequent free energy calculations based on the quasiharmonic approximation and molecular-dynamics simulations verify that the developed potential can be successfully applied to study the allotropic phase transformation between α and β phases and diffusion phenomena of pure tin.

Abstract: Interatomic potentials for pure Ca and Mg-X (X=Y,Sn,Ca) binary systems have been developed on the basis of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The potentials can describe various fundamental physical properties of pure Ca (bulk, defect and thermal properties) and the alloy behavior (structural, thermodynamic and defect properties of solid solutions and compounds) of binary systems in reasonable agreement with experimental data or first-principles and other calculations. The applicability of the developed potentials to atomistic investigations of the deformation behavior of Mg and its alloys is discussed together with some challenging points that need further attention.

Abstract: We present a new set of modified embedded-atom method parameters for the Pb-Sn system that describes many 0 K and high temperature properties including melting point, elastic constants, and enthalpy of mixing for solid and liquid Pb-Sn alloys in agreement with experiments. Then, we calculate the phase diagram of the Sn-rich side of Pb-Sn alloys utilizing a hybrid Molecular Dynamics/Monte Carlo simulation that agrees with experimental solidus and liquidus curves as well as stability of α-Sn and β-Sn. In addition, we present structure factors of Pb-Sn liquid alloys as well as temperature-dependent thermal expansion coefficients and heat capacity. Our simulations show that the ratios of the heights of the second and third peaks over the first peak for Pb-Sn liquid mixtures are maximum at Pb-0.6Sn concentration.