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arXiv · 1601.01138

Valence Imbalance of Manganese Ions between Surface and Bulk Enhanced by Fermi-Surface Structure in Layered Manganites

Ryosuke Yamamura·Takashi Hotta
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Abstract

To investigate valence imbalance phenomena between the surface and bulk in layered manganites, we analyze an eg-orbital degenerate double-exchange model with surfaces for two types of t2g spin structures. We reconfirm that the surface-induced Friedel oscillations occur in the charged structure and that the number of Mn4+ ions on the surface is larger than that in the bulk. This tendency is found to be more significant, when the eg-electron system has Fermi-surface structures with better nesting properties. The behavior of the Friedel oscillations depends on the nesting properties of the Fermi-surface curves along the direction of the oscillations, and not on the dimension of the system itself. We believe that these results will be useful for the development of high-efficiency cathodes in Li-ion batteries and catalysts.

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Ryosuke Yamamura, Takashi Hotta. 2016-01-06. Valence Imbalance of Manganese Ions between Surface and Bulk Enhanced by Fermi-Surface Structure in Layered Manganites. https://doi.org/10.1088/1742-6596/683/1/012042

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