Atomistic insights into the exothermic self-sustained alloying of Al-shell/Ni-core nanoparticle triggered by laser irradiation

By imposing a picosecond laser pulse irradiation on an Al-shell/Ni-core nanoparticle, an exothermic self-sustained alloying is triggered. Molecular dynamics simulation is implemented to get atomistic insights into the alloying process. The nanoparticle is composed by an equiatomic number of Al atoms in the shell and Ni atoms in the core. Due to the absorption of laser energy from the surface of the nanoparticle, atomic motion becomes active. The inter-diffusion of Ni and Al atoms results in thermal energy generation. It is found that the incident laser energy is responsible for controlling the degree of self-heating of the nanoparticle by governing the potential energy change during the inter-diffusion of Al-shell and Ni-core atoms.