Local structure and conductivity behaviour in Bi7WO13.5

Total neutron scattering analysis reveals details of cation coordination and vacancy distribution in Bi7WO13.5.</p

The double rare-earth substituted bismuth oxide system Bi3Y1-xYbxO6

National Science Centre Poland for project grant number 2012/05/E/ST3/02767 and the National Centre for Research and Development Poland for project grant number DKO/PL-TW1/6/2013

Structure and conductivity in tungsten doped delta-Bi3YO6

We gratefully acknowledge the STFC, for neutron beam time at the ISIS Facility, Rutherford Appleton Laboratory and Dr. Ron Smith at the ISIS facility for his help in data collection. We gratefully acknowledge the National Centre for Research and Development, Poland, for project grant number DKO/PL-TW1/6/2013

Defect structure in delta-Bi5PbY2O11.5

A detailed study of the defect structure in a di-substituted -Bi2O3 type phase, -Bi5PbY2O11.5, is presented. Using a combination of conventional Rietveld analysis of neutron diffraction data, reverse Monte Carlo (RMC) analysis of total neutron scattering data and ab initio molecular dynamics (MD) simulations, both average and local structures have been characterized. -Bi5PbY2O11.5 represents a model system for the highly conducting -Bi2O3 type phases, in which there is a higher nominal vacancy concentration than in the unsubstituted parent compound. Uniquely, the methodology developed in this study has afforded the opportunity to study both oxide-ion vacancy ordering as well as specific cation-cation interactions. Oxide-ion vacancies in this system have been found to show a preference for association with Pb2+ cations, with some evidence for clustering of these cations. The system shows a non-random distribution of vacancy pair alignments, with a preference for 100 ordering, the extent of which shows thermal variation. MD simulations indicate a predominance of oxide-ion jumps in the 100 direction