Zirconium dioxide topological surfaces with low coordination sites

Abstract

Density functional theory has been applied to model the plane and topologically complex surfaces for pure and yttrium stabilized cubic ZrO₂. For pure ZrO₂, the dominance of the (111) plane surface found in previous studies has been confirmed. Based on this surface, a series of stepped, cornered and kinked surfaces has been constructed and optimized. We observe a trend relating a decrease in stability to the decrease in the oxygen coordination number of surface Zr ions which occurs with increasing surface topological complexity. For yttrium stabilized zirconia (YSZ), the segregation of yttrium to the (111) surface predicted previously has been confirmed. As for pure ZrO₂, the most stable stepped surface topology has been identified and shown to be only slightly less stable than the planar surface.