Yttria-doped zirconia thin films with nanometric sized grains were prepared by
reactive RF sputtering and their oxygen ion conductivities were systematically
measured as a function of yttria doping with levels in the range 0.5 to
9.1mol%Y2O3. Enhanced oxygen ion conductivities, as derived from impedance
spectra, were observed when compared with values reported for bulk YSZ.
Furthermore, the peak conductivity for the films was observed to occur at
considerably reduced yttria levels, i.e., at 6.5mol%Y2O3 (at above 400C) and at
3.2mol%Y2O3 (for temperatures less than about 300C) versus 9mol%Y2O3 in bulk
Yttria-stabilised zirconia. Based upon an analysis of the Raman spectra, these
results were deduced to result from the extended meta-stability of the cubic phase
to reduced yttria levels at nanometric grain sizes.
Enhanced Ionic Conductivity and Phase Meta-Stability of Nano-Sized Thin Film
Yttria-Doped Zirconia (YDZ). W.Jung, J.L.Hertz, H.L.Tuller: Acta Materialia,
2009, 57[5], 1399-404