Cation coordination and interstitial oxygen occupancy in co-doped zirconia from first principles

摘要: Abstract The fast oxygen-conducting cubic phase of zirconia is commonly stabilized by the substitution group III cations such as yttrium and scandium, which creates vacancies in oxygen sublattice. While scandia can achieve higher conductivity freshly prepared specimens, it has previously been shown that yttria provides better stabilization characteristics than scandia, especially after extended operation at high temperatures. Density functional simulations show ions neighboring move into interstitial locations, effectively causing partial occupancy anion sites, particularly specimens containing scandia. Such occupancies stabilize substance an ordered arrangement, age-related degradation over time, explain diffuse scattering seen X-ray diffraction studies aged electrolytes. This tendency reduced increasing content mixture. Comparisons against rigid ion models bonding primarily ionic, but when become lower coordinated, strength ionic bond increases, pull away from their ideal lattice sites locations are to be stable low temperature, a phenomenon more common proximity scandium near ions.