Nanocrystalline scandia-stabilized zirconia electrolytes with scandia contents of 5.9 to 15.9 mol% were synthesized by reactive magnetron sputtering. For scandia contents ≥ 9.1mol%, the as-deposited films were pure cubic phase with <111> texture, while traces of tetragonal phase was found for lower Sc contents. Single-line profile analysis of the 111 X-ray diffraction peak yielded an out-of-plane grain size of about 10nm and a microstrain of 2.0-2.2%, regardless of scandia content, for films deposited at 400C and a bias of -70V. Films deposited at higher bias voltages showed a reduced grain size, yielding a grain size of about 6nm and a microstrain of about 2.5% at -200V and -250V with additional incorporation of argon. Temperature-dependent impedance spectroscopy of the scandia-stabilized zirconia films showed that the in-plane ionic conductivity had a maximum close to 10.7 mol% and decreased almost an order of magnitude as the scandia - content was increased to 15.9mol%. The activation energy for oxygen ion migration was determined to be between 1.30 - 1.43eV. In addition, no dependence on grain size was observed. The above observations suggested a bulk mechanism for ionic conduction.

Concentration-Dependent Ionic Conductivity and Thermal Stability of Magnetron-Sputtered Nanocrystalline Scandia-Stabilized Zirconia. M.Sillassen, P.Eklund, N.Pryds, N.Bonanos, J.Bøttiger: Solid State Ionics, 2010, 181[23-24], 1140-5