Molecular dynamics simulations on oxygen ion diffusion in strained YSZ/CeO2 superlattice

Abstract Our earlier molecular dynamics results show that the construction of a strained yttria-stabilized zirconia (YSZ)/CeO 2 superlattice considerably enhances oxygen ion diffusion. In the present study, effect of several parameters (e.g., Y 2 O 3 concentrations, stacking periodicity, and temperature) on oxygen ion diffusion in strained YSZ/CeO 2 superlattice were optimized to rationalize the understanding of the process mechanism. We found that self-diffusion coefficient of O ions reaches a maximum at around 9.1 mol% Y 2 O 3 concentration, and the increment of CeO 2 /YSZ ratio enhances oxygen ion diffusion. Moreover, activation energy for oxygen ion diffusion in the YSZ/CeO 2 superlattice (9 kcal/mol) was found to be lower than that observed in the bulk YSZ (15 kcal/mol).