Solid-liquid phase coexistence and structural transitions in palladium clusters

TL;DR

This study investigates how palladium nanoclusters transition between different solid structures during melting, revealing that fluctuations in the molten fraction lead to recrystallization into icosahedral forms.

Contribution

It demonstrates the mechanism of structural transitions during melting in palladium clusters, highlighting the role of phase coexistence and fluctuations.

Findings

Transitions from fcc and decahedral to icosahedral structures occur before melting.

Transitions happen during solid-liquid coexistence, driven by molten fraction fluctuations.

Recrystallization into icosahedral structures is observed during phase transitions.

Abstract

We use molecular dynamics with an embedded atom potential to study the behavior of palladium nanoclusters near the melting point in the microcanonical ensemble. We see transitions from both fcc and decahedral ground state structures to icosahedral structures prior to melting over a range of cluster sizes. In all cases this transition occurs during solid-liquid phase coexistence and the mechanism for the transition appears to be fluctuations in the molten fraction of the cluster and subsequent recrystallization into the icosahedral structure.