The ordering processes in Yb2Ti2O7 ceramics were studied by thermal analysis, infra-red spectroscopy, X-ray diffraction, scanning electron microscopy and electrical conductivity measurements. The Yb2Ti2O7 was obtained by co-precipitation, followed by freeze-drying and thermal annealing (350 to 1670C). The existence of the fluorite–pyrochlore low-temperature transition near to 800C and the pyrochlore–fluorite high-temperature transition near to 1700C was established. The conductivity of Yb2Ti2O7 sintered at 1670C seems to be ionic at 300 to 950C, with a bulk activation energy of 0.81eV. The Yb2Ti2O7 ceramics had a grain size of about 30nm for a wide range of sintering temperatures (1400 to 1670C).

Synthesis and Conductivity of Yb2Ti2O7 Nanoceramics. A.V.Shlyakhtina, J.C.C.Abrantes, L.L.Larina, L.G.Shcherbakova: Solid State Ionics, 2005, 176[17-18], 1653-6