Melting curves and structural properties of tantalum from the modified-Z method

Abstract

The melting curves and structural properties of tantalum (Ta) are investigated by molecular dynamics simulations combining with potential model developed by Ravelo et al. [Phys. Rev. B 88, 134101 (2013)]. Before calculations, five potentials are systematically compared with their abilities of producing reasonable compressional and equilibrium mechanical properties of Ta. We have improved the modified-Z method introduced by Wang et al. [J. Appl. Phys. 114, 163514 (2013)] by increasing the sizes in L x and L y of the rectangular parallelepiped box (L x ¼ L y (L z). The influences of size and aspect ratio of the simulation box to melting curves are also fully tested. The structural differences between solid and liquid are detected by number density and local-order parameters Q 6. Moreover, the atoms' diffusion with simulation time, defects, and vacancies formations in the sample are all studied by comparing situations in solid, solid-liquid coexistence, and liquid state. V

Melting of bcc crystal Ta without the Lindemann criterion

“…Ta atoms interact with an embedded atom method potential [24]. The potential has been applied for the melting process [25,26]. Several systems are tested that contain different number of atoms from 500, 4000, 16 000, 32 000 to 500 000 atoms arranged in bcc structure with periodic boundary conditions in three directions.…”

Modeling the melting of multicomponent systems: the case of MgSiO3 perovskite under lower mantle conditions

“…In this study we estimate the melting temperature of bridgmanite at 25 GPa and 120 GPa using the so-called two-phase model (2P phase) and ab initio molecular dynamics. This method avoids overheating issues typical of melting a fully solid system and has been used in a number of studies to produce melting temperatures for a range of materials 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 . As described in Methods section, a system of coexisting solid and liquid is set up and allowed to evolve through time.…”