Fast oxygen diffusion in bismuth oxide probed by quasielastic neutron scattering

We present the first, to our knowledge, study of solid state oxygen translational diffusion by quasielastic neutron scattering. Such studies in the past might have been precluded by relatively low diffusivities of oxygen anions in the temperature range amenable to neutron scattering experiments. To explore the potential of the quasielastic scattering technique, which can deduce atomic diffusion jump length of oxygen anions through the momentum transfer dependence of the scattering signal, we have selected the fastest known oxygen conductor, bismuth oxide. We have found the oxygen anion jump length in excellent agreement with the nearest oxygen-vacancy distance in the anion sublattice of the fluorite-related structure of bismuth oxide.