Porosity effects on oxygen ions diffusion in the yttria-stabilized zirconia (YSZ) by molecular dynamics simulation

In this paper, the porosity effects on oxygen ions diffusion was investigated in the yttria-stabilized zirconia (YSZ) by molecular dynamics simulation (MD). Different models were simulated to elucidate the role of yttria (Y2O3) concentration (3 to 8 mol% Y2O3), number of pores and pores density and structure (cubic and tetragonal lattice) on the oxygen ions diffusion in YSZ system. MD simulation results showed that the diffusion coefficient of the tetragonal YSZ was smaller than that of the cubic YSZ, the maximum of oxygen ions diffusion coefficient exhibited in the 6 mol% Y2O3 among all the tetragonal YSZ systems. From MD simulation results, it was found that the pores in the YSZ system were retarding the oxygen ions diffusion. For constant porosity, smaller single pore volume resulted in lower D, while higher total porosity also led to smaller D.