Thermally stable, stoichiometric, cubic yttria-stabilized zirconia thin-film

electrolytes were synthesized by reactive pulsed dc magnetron sputtering from a

Zr–Y (80/20at%) alloy target. Films deposited at floating potential had a <111>

texture. Single-line profile analysis of the 111 X-ray diffraction peak yielded a

grain size of ~20nm and a microstrain of ~2% regardless of deposition temperature.

Films deposited at 400 C and selected bias voltages in the range from −70 to

−200V showed a reduced grain size for higher bias voltages, yielding a grain size

of ~6nm and a microstrain of ~2.5% at bias voltages of −175 and −200 V with

additional incorporation of argon. The films were thermally stable; very limited

grain coarsening was observed up to an annealing temperature of 800C.

Temperature-dependent impedance spectroscopy analysis of films with Ag

electrodes showed that the in-plane ionic conductivity was within one order of

magnitude higher in films deposited with substrate bias corresponding to a

decrease in grain size compared to films deposited at floating potential. This

suggested that there was a significant contribution to the ionic conductivity from

grain boundaries. The activation energy for oxygen ion migration was determined

to be between 1.14 and 1.30eV.

Ionic Conductivity and Thermal Stability of Magnetron-Sputtered Nanocrystalline

Yttria-Stabilized Zirconia. M.Sillassen, P.Eklund, M.Sridharan, N.Pryds,

N.Bonanos, J.Bøttiger: Journal of Applied Physics, 2009, 105[10], 104907