Transition from Icosahedral to Decahedral Structure in a Coexisting Solid-Liquid Nickel Cluster

TL;DR

This study uses molecular dynamics to explore structural transitions in a nickel cluster, revealing a shift from icosahedral to decahedral form driven by wetting behavior near melting.

Contribution

It uncovers a novel structural transition in nickel clusters from icosahedral to decahedral during melting, driven by wetting preferences, using detailed molecular dynamics simulations.

Findings

Transition from icosahedral to decahedral structure near melting point

Decahedral structure becomes fully wet by melt before complete melting

Structural transition driven by wetting behavior of the melt

Abstract

We have used molecular dynamics simulations to construct a microcanonical caloric curve for a 1415-atom Ni icosahedron. Prior to melting the Ni cluster exhibits static solid-liquid phase coexistence. Initially a partial icosahedral structure coexists with a non-wetting melt. However at energies very close to the melting point the icosahedral structure is replaced by a truncated decahedral structure which is almost fully wet by the melt. This structure remains until the cluster fully melts. The transition appears to be driven by a preference for the melt to wet the decahedral structure.