Ab Initio Calculations of Pristine and Doped Zirconia 5 (310)/[001] Tilt Grain Boundaries

The structure of the cubic-ZrO2 symmetrical tilt 5 (310)/ [001] grain boundary is examined using density functional theory within the local density and pseudopotential approxi-mations. Several pristine stoichiometric grain-boundary struc-tures are investigated and compared with Z-contrast scanning transmission electron microscopy and electron energy loss spectroscopy results. The lowest-energy grain-boundary struc-ture is found to agree well with the experimental data. When Y3 is substituted for Zr4 at various sites in the lowest-energy grain-boundary structure, the calculations indicate that Y3 segregation to the grain boundary is energetically preferred to bulk doping, in agreement with experimental results. I