Crystals of Y2O3 and CeO2-doped Y2O3 were prepared by oriented crystallization in a cold container in order to compare the influence of ceria additions on the quality of yttria crystals grown by this method. Ceria addition resulted in an increased phase stability of the melt as well as the solid phase. The crystallization of CeO2-doped Y2O3 had a rod-shaped character in comparison with the mosaic structure of undoped yttria. The distribution of cerium cations in the crystal was inhomogeneous and a part of them could be also present in the trivalent state. The addition of ceria increased the electrical conductivity of yttria due to the interstitial O ions, vacancies and polarons according to the given conditions. An anomaly observed on the Arrhenius dependencies of conductivity versus temperature at 493 to 593K could be explained by the excess vacancies formed by dislocations created during the crystallization of mosaic blocks and rods from the high temperatures in the cold container. The behavior of electrical conductivity was in a good agreement with that of microhardness.

The Influence of Ceria Addition on the Quality of Grown Yttria Crystals, their Crystalline and Defect Structures. M.Hartmanová, E.E.Lomonova, V.Navrátil, F.Kundracik, I.Kostič: Materials Science and Engineering B, 2004, 113[1], 1-6