Premelting of Al nonperfect (111) surface

TL;DR

This study uses molecular dynamics simulations to explore how perfect and nonperfect aluminum (111) surfaces melt, revealing that nonperfect surfaces tend to premelt at temperatures below the bulk melting point, with atoms exhibiting higher velocities.

Contribution

It provides new insights into the melting behaviors of perfect and nonperfect Al (111) surfaces, highlighting the role of surface imperfections in premelting phenomena.

Findings

Perfect surface superheats by about 80 K above Tm.

Nonperfect surface premelts approximately 45 K below Tm.

Atoms on nonperfect zones have higher velocities indicating early melting.

Abstract

Melting behaviors of aluminum (111) perfect/nonperfect surfaces, characterized by structure ordering parameter, have been investigated by classical molecular dynamics simulation with embedded atom method potential. Al (111) perfect surface has a superheating temperature above bulk Al melting point Tm, in this work, by about 80 K. Al nonperfect (111) surface has somewhat different local lattice structure from that on (111) perfect surface. Al nonperfect (111) surfaces tempt to premelt when temperature is less than Tm, in our simulation, by about 45 K. Aluminum atoms on the nonperfect surface zones are the sources of surface melting, and have larger velocities than those on the perfect surface zones.