Multiple Li Positions inside Oxygen Octahedra in Lithiated TiO2 Anatase

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• 作者：Marnix Wagemaker ; Gordon J. Kearley ; Ad A. van Well ; Hannu Mutka ; and Fokko M. Mulder
• 刊名：Journal of the American Chemical Society
• 出版年：2003
• 出版时间：January 22, 2003
• 年：2003
• 卷：125
• 期：3
• 页码：840 - 848
• 全文大小：198K
• 年卷期：v.125,no.3(January 22, 2003)
• ISSN：1520-5126

文摘

Intercalation of Li in TiO₂ anatase results in a phase separation in a Li-poor and a Li-rich phase.The local lithium configuration in the coexisting crystallographic phases is resolved by detailed analysis ofneutron diffraction data. In each of the phases, two distinct positions within the octahedral interstices arefound, with a temperature-dependent occupancy. A combination of quasi-elastic neutron scattering andforce field molecular dynamics simulations shows that Li is hopping on a picosecond time scale betweenthe two sites in the octahedral interstices. The results also suggest a specific Li arrangement along thecrystallographic a direction, albeit without long range order. It is likely that multiple discrete Li sites withina distorted oxygen octahedron occur not only in intercalated TiO₂ anatase but also in other (transitionmetal) oxides.