Melting, bubble-like expansion and explosion of superheated plasmonic nanoparticles

TL;DR

This study uses time-resolved diffraction imaging and simulations to explore how superheated plasmonic silver nanoparticles undergo melting, cavitation, and explosive disintegration depending on excitation strength, revealing the role of metastable states.

Contribution

It combines experimental imaging with molecular dynamics simulations to elucidate the phase transition pathways of superheated nanoparticles under plasmonic heating, highlighting the importance of crossing stability limits.

Findings

Different excitation strengths lead to melting, cavitation, or explosion.

Simulations match experimental results and show trajectories through the phase diagram.

Outcomes depend on crossing the stability limit of superheated liquid.

Abstract

We report on time-resolved coherent diffraction imaging of gas-phase silver nanoparticles, strongly heated via their plasmon resonance. The x-ray diffraction images reveal a broad range of phenomena for different excitation strengths, from simple melting over strong cavitation to explosive disintegration. Molecular dynamics simulations fully reproduce this behavior and show that the heating induces rather similar trajectories through the phase diagram in all cases, with the very different outcomes being due only to whether and where the stability limit of the metastable superheated liquid is crossed.