Electrical properties of plasma-sprayed yttria-stabilized zirconia films

Yttria-stabilized zirconia films, 100 to 200 m thick, were prepared by plasma spraying. To improve the density, the films were sintered in vacuum at 2000C (sample 1) or 2100C (sample 2) for 3 h and then annealed in air at 1450C for 3 h to restore the oxygen stoichiometry. The electrical properties were investigated by complex impedance spectroscopy. The results are compared with those obtained on sintered pellets prepared with the same powders used for spraying an on commercial single crystals. The ionic conductivity and the activation energies of sprayed films and single crystals are found to be very similar, and no grain-boundary effect was observed in the film complex impedance plots of the films. These results are explained by the high density and purity of the sprayed films. In conclusion, films of yttria-stabilizd zirconia prepared by plasma spraying and densified at high temperature can be used, as solid electrolytes, in electrochemical devices. 5pp 6fig 2tab