ac impedance study of zirconia doped with yttria and calcia

The ionic conductivity in the system (1 - 0.08x - 0.12y)ZrO2-0.08xY(2)O(3)- 0.12yCaO (where x + y = 1 and y = 0-1) has been investigated using the comp lex impedance technique at 523-973 K. Doping CaO in the ZrO2-Y2O3 system ma y result in an increase in the activation energy for lattice conduction and depress the grain-boundary effect on conduction. Analysis of the temperatu re dependence of the lattice conductivity, according to the familiar Arrhen ius equation, predicts that the examined ternary system map exhibit greater lattice conductivity than the ZrO2-Y2O3 binary system at higher temperatur es. Preliminary explanations for these experimental phenomena and predictio ns also have been presented.