Theoretical Study on the Effects of Oxygen Doping on the Lithium Ion Conductive Perovskite-Type Manganese Fluoride of KxBa(1-x)/2MnF3

Previously, we demonstrated that the lithium ion conduction in the perovskite-type manganese fluoride is attributed to counter cation-site vacancy mechanism. The divalent counter cation-doped KxBa(1-x)/2MnF3 was theoretically predicted as the lithium ion conductor in the perovskite-type manganese fluoride. In this study, we considered the oxygen doping for KxBa(1-x)/2MnF3 to realize the higher lithium ion conductivity. It is because lithium ion forms the stronger ionic bond with the doped oxygen anion. The hybrid-DFT calculations were performed to investigate the lithium ion conduction in the oxygen-doped KxBa(1-x)/2MnF3. The calculation results were discussed from the viewpoints of the potential energy curve, electron densities, and charge and spin densities. The effect of the lithium ion fluctuation was also discussed by calculating the ratio of the diffusion coefficients. Finally, we theoretically predicted the ideal oxygen-doped structure for KxBa(1-x)/2MnF3. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 3659-3665, 2009