Abstract
Results of structural studies and ionic conductivity of solid solutions (ZrO2)1- x(Sc2O3)x (x = 0.08 – 0.10) doped with 1 mol.% Y2O3, Yb2O3иСeO2 are presented. Crystals were grown by directional crystallization of melt in cold container. Studies of phase compositions were carried out by means of X-ray diffraction and Raman spectroscopy. Transport properties were studied by impedance spectroscopy in the temperature range of 400–900°С. It was shown that uniform transparent single crystals were obtained only for compositions of (ZrO2)0.89(Sc2O3)0.1(Y2O3)0.01 and (ZrO2)0.90(Sc2O3)0.09(Yb2O3)0.01. Stabilization of highly-symmetric phase in crystals co- doped with Yb2O3 happens for a lower concentration of Sc2O3 in solid solution than for crystals co-doped with Y2O3. Co-doping by ceria did not give an opportunity to obtain the single-phase cubic solid solution. It was also shown, that the conductivity ofcrystalsdepends on the amount of Sc2O3 in solid solutions. It was detected that conductivity values for tetragonal crystals at 900oC are close and they equal to about 0.1 S/cm by the order of magnitude. Crystals with the composition of (ZrO2)0.9(Sc2O3)0.09(Yb2O3)0.01 have maximal conductivity in all the temperature range studied. The conductivity value of these crystals at a temperature of 900°С is comparable to the similar value for (ZrO2)0.9(Sc2O3)0.1 crystals. However, unlike the (ZrO2)0.9(Sc2O3)0.1 crystal containing the rhombohedral phase, the (ZrO2)0.90(Sc2O3)0.09(Yb2O3)0.01 sample is a single-phase pseudo-cubic.