Modeling ionic conduction in γ-Bi2VO5.5

Abstract

?-Bi2VO5.5 family oxides has potential to play important role in solid oxide fuel cell, especially as the electrolyte due to their high ionic conductivity. In this work, oxide conduction in γ-Bi2VO5.5 is modeled based on bond valence sum (BVS) method. In γ-Bi2VO5.5, there are oxide vacancies at the equatorial position in the perovskite-like layers. These vacancies can facilitate oxide movement. The γ-Bi2VO5.5 model was built in a primitive structure with the entire V coordination in one layer are tetrahedron and entire V coordination in the next layer are octahedron. Oxygen movement, based on BVS result, mainly occurs in equatorial site i.e. on [140] direction. The minimum achieved BVS value was 1.320, which is considered as a site that has large cavity and facilitates oxygen hopping.