Superheating and solid-liquid phase coexistence in nanoparticles with non-melting surfaces

TL;DR

This paper introduces a phenomenological model explaining how nanoparticles with non-melting surfaces can exhibit superheating and coexistence of solid and liquid phases, supported by molecular dynamics simulations.

Contribution

The study presents a new model for nanoparticle melting that accounts for partial wetting surfaces and predicts superheating phenomena.

Findings

Solid nanoparticles can remain stable above bulk melting points.

Coexistence of solid and liquid phases occurs via a first-order transition.

Model predictions align with molecular dynamics simulations of aluminum nanoparticles.

Abstract

We present a phenomenological model of melting in nanoparticles with facets that are only partially wet by their liquid phase. We show that in this model, as the solid nanoparticle seeks to avoid coexistence with the liquid, the microcanonical melting temperature can exceed the bulk melting point, and that the onset of coexistence is a first-order transition. We show that these results are consistent with molecular dynamics simulations of aluminum nanoparticles which remain solid above the bulk melting temperature.