Variable Temperature Neutron Diffraction Study of the Oxide Ion Conductor BaVWO.

BaVWO is an oxide ion conductor with a bulk conductivity of 5.0 × 10 S cm at 600 °C. BaVWO is anomalous to the other BaM'M″O (M' = Nb; M″ = Mo, W) oxide ionic conductors, as it exhibits cation order with vanadium and tungsten on the M1 site only.

Investigation of the Crystal Structure and Ionic Pathways of the Hexagonal Perovskite Derivative BaVMoO.

The hexagonal perovskite derivatives BaNbMoO, BaNbWO, and BaVWO have recently been reported to exhibit significant oxide ion conductivity. Here, we report the synthesis and crystal structure of the hexagonal perovskite derivative BaVMoO. Rietveld refinement from neutron and X-ray diffraction data show that the cation vacancies are ordered on the M2 site, leading to a structure consisting of palmierite-like layers of M1O polyhedra separated by vacant octahedral layers.