On the anomalous diffusion of proton in Y-doped BaZrO3 perovskite oxide.

Proton transport in perovskite oxides (ABO 3) is a complex dynamical process involving hydroxide ion rotation and proton transfer. Combining ab initio molecular dynamics (AIMD) and machine-learning molecular dynamics (MLMD) simulations of proton dynamics in Y-doped BaZrO 3 perovskite oxide, we systematically illustrate the anomalous characteristics of proton motion. At short times, proton performs superdiffusion through the O H wag and proton transfer. At intermediate times, the larger rotation angle results in the larger plateau value. At longer times, proton diffusion first becomes subdiffusive due to the hydroxide ion rotations then gradually turns to normal diffusion. A theoretical model is also offered to quantitatively describe this abnormal proton diffusion. In all, this work provides a more complete understanding of proton dynamics in perovskite oxides. • A machine-learning potential is developed to perform MD simulations with DFT accuracy. • The anomalous characteristics of proton motion in Y-doped BaZrO 3 are systematically illustrated at different time intervals. • A theoretical model is proposed to quantitatively describe the abnormal proton diffusion in Y-doped BaZrO 3. [ABSTRACT FROM AUTHOR]