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Charge-ordering phase transition and order-disorder effects in the Raman spectra of NaV2O5

M. J. Konstantinovic·M. Isobe·Y. Ueda
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Abstract

In the ac polarized Raman spectra of NaV2O5 we have found anomalous phonon broadening, and an energy shift of the low-frequency mode as a function of the temperature. These effects are related to the breaking of translational symmetry, caused by electrical disorder that originates from the fluctuating nature of the V {4.5+} valence state of vanadium. The structural correlation length, obtained from comparisons between the measured and calculated Raman scattering spectra, diverges at T< 5 K, indicating the existence of the long-range charge order at very low temperatures, probably at T=0 K.

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M. J. Konstantinovic, M. Isobe, Y. Ueda. 2001-01-31. Charge-ordering phase transition and order-disorder effects in the Raman spectra of NaV2O5. https://doi.org/10.1103/physrevb.63.100303

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