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Infrared response of ordered polarons in layered perovskites

P. Calvani·A. Paolone·P. Dore·S. Lupi·P. Maselli·P. G. Medaglia·S-W. Cheong
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Abstract

We report on the infrared absorption spectra of three oxides where charged superlattices have been recently observed in diffraction experiments. In La$_{1.67}$Sr$_{0.33}$NiO$_4$, polaron localization is found to suppress the low-energy conductivity through the opening of a gap and to split the $E_{2u}$-$A_{2u}$ vibrational manifold of the oxygen octahedra. Similar effects are detected in Sr$_{1.5}$La$_{0.5}$MnO$_4$ and in La$_2$NiO$_{4+y}$, with peculiar differences related to the type of charge ordering.

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P. Calvani, A. Paolone, P. Dore, S. Lupi, P. Maselli, P. G. Medaglia, S-W. Cheong. 1996-09-13. Infrared response of ordered polarons in layered perovskites. https://doi.org/10.1103/physrevb.54.r9592

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