Scandia-stabilized zirconia films were epitaxially grown on sapphire (00•1) substrates by oxygen-plasma-assisted molecular beam epitaxy. The cubic phase was found to exist over a wider dopant concentration range than previously observed (4.6–17.6mol%Sc2O3). The monoclinic phase was observed for dopant concentrations of 1.5 mol.% and 22.5mol%. An increase in the fraction of the monoclinic phase relative to the cubic phase decreased the ionic conductivity. The highest conductivity in the temperature range of 460–900C was observed for 9.9 mol.% Sc2O3. Atomistic computer simulations showed that the observed composition dependence could be related to changes in migration barriers for O2− ion transport with Sc3+ substitution of Zr4+ ions.

Integrated Experimental and Modeling Study of Ionic Conductivity of Scandia-Stabilized Zirconia Thin Films. Z.Q.Yu, R.Devanathan, W.Jiang, P.Nachimuthu, V.Shutthanandan, L.Saraf, C.M.Wang, S.V.N.T.Kuchibhatla, S.Thevuthasan: Solid State Ionics, 2010, 181[8-10], 367-71