Studies were conducted based on the nuclear/electron density distributions obtained by a combined technique including Rietveld refinement, the maximum entropy method and the related pattern fitting of the neutron/synchrotron powder diffraction data measured at high temperatures. Diffusion paths along the <100> directions were observed in various ionic conductors with fluorite-type structures such as δ-Bi1.4Yb0.6O3, Ce0.93Y0.07O1.96, Y0.785Ta0.215O1.715 and α-CuI. The diffusion paths of oxide ions in the cubic perovskite-type (La0.8Sr0.2)(Ga0.8 Mg0.15Co0.05)O3−δ exhibited an arc shape away from the (Ga0.8Mg0.15Co0.05) cation, forming a 3-dimensional network of curved diffusion paths. Double perovskite-type La0.64(Ti0.92Nb0.08)O2.99 shows a similar diffusion path near the (004) planes, forming a 2-dimensional network of curved diffusion paths. The curved feature of the diffusion paths was observed in various oxide-ion conductors such as δ-Bi1.4Yb0.6O3, (La0.8Sr0.2)(Ga0.8 Mg0.15Co0.05)O3−δ and La0.64(Ti0.92Nb0.08)O2.99, as well as in the Cu-cation conductor α-CuI and Li-cation conductor La0.62Li0.16TiO3.

Crystal Structures, Structural Disorders and Diffusion Paths of Ionic Conductors from Diffraction Experiments. M.Yashima: Solid State Ionics, 2008, 179[21-26], 797-803