AbstractThe ZrO2:Y2O3 solid solution formation has been followed by impedance spectroscopy and X-ray analysis. The experimental sequence, after mixing 8 mol% Y2O3 to ZrO2, was: attrition milling the mixture, drying, weighing, cold pressing, thermally treating at several different temperatures and times, performing the X-ray diffraction measurements at room temperature, applying metallic electrodes, and performing the impedance spectroscopy measurements in the 300°C-600°C temperature range. A good correlation was found between the decrease of the yttria main diffraction line and the increase of the stabilized zirconia main diffraction line, showing that solid solution is attained at the expenses of yttria, as expected. The impedance spectroscopy data Z(ω, T, t) show that the bulk response follows a t1/2 law, an evidence of yttrium diffusion to zirconia. Moreover, a relationship is found between the bulk resistivity and the elimination of ion blockers for increasing sintering times. The result allowed for the determination of the activation energy for the diffusion of the slowest diffusing species (Zr4+) in ZrO2:Y2O3.