The first data on monocrystalline gadolinia-doped ceria were presented. The crystal was prepared by inductive melting in a cold crucible. The cell parameter of 0.5426nm was estimated by means of X-ray powder diffraction. The conductivity was measured, by using impedance spectroscopy, in N, O or air at temperatures of between 190 and 550C. The activation energy was found to be 1.1eV. The diffusion and surface exchange coefficients were determined by means of 18O isotope exchange and secondary ion mass spectrometry. The activation energy for diffusion was found to be 1.16eV. A transition, from low to high, in the activation energy of the surface exchange coefficient was seen at about 650C.

Oxygen Ion Diffusivity, Surface Exchange and Ionic Conductivity in Single Crystal Gadolinia Doped Ceria. E.Ruiz-Trejo, J.D.Sirman, J.M.Baikov, J.A.Kilner: Solid State Ionics, 1998, 113-115, 565-9