The microscopic mechanism of oxygen diffusion in yttria-stabilized zirconia was investigated by means of a polyhedron analysis. It was shown that the probability of finding an O ion in a tetrahedron increased as the likelihood of Y ions at the corners of the tetrahedron increased. This tendency became marked with increasing dopant concentration; consistent with the fact that the oxygen coordination number for Y ions was larger than that for Zr ions. By studying the oxygen migration between tetrahedra in the [100] direction, it was found that the migration occurred preferentially between tetrahedra having a common Zr-Zr edge, and that Y ions restricted the diffusion paths of O ions. Restriction by the Y-Y edge caused a decrease in oxygen diffusion with increasing dopant concentration.

Molecular Dynamics Studies of Yttria Stabilized Zirconia. II. Microscopic Mechanism of Oxygen Diffusion. Shimojo, F., Okazakl, H.: Journal of the Physical Society of Japan, 1992, 61[11], 4106-18