Spontaneously Generated Stress Waves inside Nanoparticles during Rapid Heating in Molecular Dynamics Simulation

Metallic nanoparticles are one of the widely used materials whose structural properties significantly affect their performance. Thermal processes have the potential to modify the structure of nanoparticles, enabling the active adjustment of nanoparticle properties. We conducted molecular dynamics simulations and observed the spontaneous generation of statistical stress waves inside nanoparticles during thermal processes. These stress waves emerged rapidly during heating and subsided once the nanoparticle was fully melted. Our findings indicate that stress waves play a crucial role in redistributing energy during surface melting, as is the existence of the solid–liquid interface. These waves carry energy across the interface, with the tangential force trapped inside the solid phase, which manifests in temperature gradients within the nanoparticle. This work provides deep insight into the stress information and mechanisms governing the energy distribution of nanoparticles during thermal processes, which may offer inspiration for new ways of altering the nanoparticle’s structure.