Laser-Induced Melting and Coalescence of Nanoparticle Clusters Captured in Real Time

The light–matter interactions that occur during the laser processing of metal particles play a significant role in causing melting, fusion, and various other dynamic behaviors in these materials. Observing these behaviors at the nanoscale, temporally and spatially, allows for a more comprehensive understanding of the intricate processes involved in laser-material interactions. This study uses clusters of nanoparticles irradiated by a single nanosecond laser pulse and imaged at precise delay times through ultrafast transmission electron microscopy to investigate the dynamics and time scales of nanoparticle melting and coalescence. These dynamic events are shown to be manipulated through cluster size and location both experimentally and through finite element analysis methods. The substrate deformations and subsequent interactions are determined to strongly affect the exposed region and can influence the fusion process. This study provides valuable insights into laser-based fabrication behaviors of nanoparticle clusters for nanoscale structures.