Kinetics of the formation of a new phase in nanoparticles

We present Monte Carlo simulations of the formation of a new phase (e.g., hydride in metal) during uptake of atoms by a nanoparticle. The corresponding kinetics exhibit a short initial stage, which is sensitive to the specification of the subsurface layers, and a more universal long stage with the time scale proportional to Lz, where L is the lattice size, and 2.3 ⩽ z ⩽ 3 is the exponent dependent on the diffusion dynamics. For realistic diffusion dynamics, the model also predicts the third late stage when the growth of a new phase becomes very slow compared to that observed during the former stages.