A Melting‐Point Energy Window for Defect‐Induced Energy Release in Copper Nanoparticles

Metal nanoparticles produced by wire electrical explosion inherently contain structural defects that generate extra stored energy, making them promising additives for energetic materials. In this study, ReaxFF molecular dynamics simulations were performed to investigate the melting behavior and energy release mechanisms of defect‐containing copper nanoparticles. Copper nanoparticles with diameters of 2–4 nm and vacancy defect concentrations of 2%–10% were analyzed using radial distribution functions, potential energy, face‐centered cubic (FCC) fraction, and extra stored energy. The results show that the transition temperature decreases with decreasing particle size, consistent with the Gibbs–Thomson effect, and that melting initiates at low‐coordination surface atoms before propagating into the FCC core. Notably, the extra stored energy exhibits sharp peaks at the melting transition, reaching approximately 580 kcal/mol at 10% defect concentration. These findings demonstrate that defect‐induced energy is rapidly released during melting, highlighting the potential of defect‐engineered copper nanoparticles as additives for ignition and combustion enhancement in energetic materials.