Surface structure and solidification morphology of aluminum nanoclusters

TL;DR

This study uses molecular dynamics simulations to analyze the surface structure and solidification morphology of aluminum nanoclusters, revealing dominant crystal planes and surface energy characteristics that influence their shape after solidification.

Contribution

It provides detailed insights into the surface crystal planes and energy minimization in aluminum nanoclusters, predicting their equilibrium shape post-solidification.

Findings

Al cluster surfaces are mainly (111) and (001) planes.

(110) planes are not observed on the surfaces.

Optimal surface energy occurs when (001) planes cover 25% of the surface.

Abstract

Classical molecular dynamics simulation with embedded atom method potential had been performed to investigate the surface structure and solidification morphology of aluminum nanoclusters Aln (n = 256, 604, 1220 and 2048). It is found that Al cluster surfaces are comprised of (111) and (001) crystal planes. (110) crystal plane is not found on Al cluster surfaces in our simulation. On the surfaces of smaller Al clusters (n = 256 and 604), (111) crystal planes are dominant. On larger Al clusters (n = 1220 and 2048), (111) planes are still dominant but (001) planes can not be neglected. Atomic density on cluster (111)/(001) surface is smaller/larger than the corresponding value on bulk surface. Computational analysis on total surface area and surface energies indicates that the total surface energy of an ideal Al nanocluster has the minimum value when (001) planes occupy 25% of the total surface area. We predict that a melted Al cluster will be a truncated octahedron after equilibrium solidification.