Neutron diffraction study of occupancy and positional order of oxygen ionsin phase stabilized cubic bismuth oxides

The high temperature cubic bismuth oxide phase stabilized with lanthanide d opants undergoes an order-disorder transition of the anion sublattice at ab out 600 degreesC. When annealed at temperatures below the transition temper ature, oxygen ion conductivity undergoes a decay. Neutron diffraction studi es have been performed to investigate the structural changes in the anion s ublattice that result in the conductivity decay and the effect of dopant on the kinetics of decay. Atomic displacement parameters of oxygen ions were determined at low temperatures for the ordered and disordered structures to determine the static disorder in the oxygen sublattice of ordered and diso rdered structures. (C) 2001 Elsevier Science B.V. All rights reserved.