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Charge ordering signatures in the optical properties of beta-Na0.33V2O5

C. Presura·M. Popinciuc·P. H. M. van Loosdrecht·D. van der Marel·M. Mostovoy·T. Yamauchi·Y. Ueda
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Abstract

Temperature dependent optical spectra are reported for beta-Na0.33V2O5. The sodium ordering transition at T_Na = 240 K, and in particular the charge ordering transition at T_MI = 136 K strongly influence the optical spectra. The metal-insulator transition at \tmi leads to the opening of a psuedogap (\hbarω= 1700 cm-1), and to the appearance of a large number of optical phonons. These observations, and the presence of a mid-infrared band (typical for low dimensional metals) strongly suggests that the charge carriers in beta-Na0.33V2O5 are small polarons.

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C. Presura, M. Popinciuc, P. H. M. van Loosdrecht, D. van der Marel, M. Mostovoy, T. Yamauchi, Y. Ueda. 2002-11-28. Charge ordering signatures in the optical properties of beta-Na0.33V2O5. https://doi.org/10.1103/physrevlett.90.026402

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