Molecular Dynamics Simulation of the Fast Ion Conductor δ-Bi₂O₃. II. Sub-lattice Structure

Abstract

The results of molecular dynamics (MD) simulations of δ-B₂O₃ are analyzed with a view to obtaining an increased understanding of the structure of the Bi³⁺ and O^2- sub-lattices. The existence of cube-edge O^2- interstitials and of Willis-like disorder is confirmed by density maps. The onset of fast-ion conduction is associated with changes in the structure of both sub-lattices. Interpretation of the results suggests the existence of more than one fluorite form, differing in the structure of the O^2- sublattice.

Key Words:

• Bismuth oxide
• bismuth sesquioxide
• fluorite
• molecular dynamics
• fast-ion conduction