Xenon Diffusion Mechanism and Xenon Bubble Nucleation and Growth Behaviors in Molybdenum via Molecular Dynamics Simulations

The behaviors of xenon in molybdenum were studied using molecular statics and molecular dynamics simulations. The diffusion mechanism of xenon atoms was studied combining molecular dynamics, nudged elastic band, and temperature-accelerated dynamics methods. The vacancy-assisted diffusion mechanism was analyzed and the corresponding energy barriers were calculated. The clustering process of scattered xenon atoms was studied at an elevated temperature. Xenon bubbles were observed to form when the concentration of xenon atoms exceeded a threshold concentration value. Meanwhile, the interaction of xenon bubble and vacancies was investigated via the nudged elastic band method. The results showed that there exists a region around the xenon bubble where the migration energy of vacancy is significantly influenced. This work provides useful insights towards a better understanding of the behaviors of xenon in molybdenum.