RESUMO
An effective interatomic potential consisting of two- and three-body covalent interactions is used here to study the properties of gallium phosphide by molecular dynamics simulations. The many-body interatomic potential accounts for the energy scale, length scale and mechanical properties of GaP. At atmospheric pressure, the calculated melting temperature, linear thermal expansion, vibrational density of states and specific heat are in excellent agreement with experimental results. The structural phase transition induced by hydrostatic pressure at 27 GPa is also in quite good agreement with experimental findings. We also studied the energy of vacancy formation in the GaP lattice and the surface energy, which is in reasonable agreement with experimental data.
RESUMO
This work addresses the question on how the glass-forming ability (GFA) of a binary Pd-Ni metallic glass can be enhanced by the alloying effect of Pt. The structural features and slow dynamics of liquid and glassy states on both alloys are investigated by molecular dynamics simulations. Both alloys show typical features of glassy dynamics, namely, the non-Arrhenian behavior of diffusion and relaxation and the fractional Stokes-Einstein relation validity at low temperatures. On the basis of the analysis of the dynamical susceptibilities, we demonstrate that there is a strong influence of the alloying effect on the collective motion of the species, revealing that the GFA of the binary liquid increases with Pt alloying.