MOLECULAR-DYNAMICS STUDIES OF YTTRIA STABILIZED ZIRCONIA .1. STRUCTURE AND OXYGEN DIFFUSION

The structure and dynamical properties of oxygen conductor yttria stabilized zirconia, (ZrO2)1-x(Y2O3)x, are investigated for three dopant concentrations of 4.85, 10.2 and 22.7 mol%Y2O3 Using a method of molecular dynamics simulation. It is shown that a Y-O nearest neighbor distance is longer than that for Zr-O, and an oxygen coordination number for Y ion is a little larger than that for Zr ion in all dopant concentrations. The self-diffusion constant of O ions, D, shows a maximum at 10.2 mol%Y2O3 with increasing the dopant concentration. These results are in agreement with experimental measurements. It is shown that dopant Y ions play an important role in such notable behavior of oxygen diffusion.