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X-ray Anomalous Scattering Study of a Charge-Ordered State in NaV2O5

H. Nakao·K. Ohwada·N. Takesue·Y. Fujii·M. Isobe·Y. Ueda·M. v. Zimmermann·J. P. Hill·D. Gibbs·J. C. Woicik·I. Koyama·Y. Murakami
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Abstract

Charge ordering of V4+ and V5+ in NaV2O5 has been studied by an X-ray diffraction technique using anomalous scattering near a vanadium K-absorption edge to critically enhance a contrast between the two ions. A dramatic energy dependence of the superlattice intensities is observed below Tc=35 K. Consequently, the charge ordering pattern is the zigzag-type ladders with the unit cell 2a*2b*4c, but not the chain-type originally proposed for the spin-Peierls state. Charge disproportionation suggested in our model as the average valence V^{4.5+-delta_c/2} is observed below T_C, showing continuous variation of delta_c as a function of temperature.

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H. Nakao, K. Ohwada, N. Takesue, Y. Fujii, M. Isobe, Y. Ueda, M. v. Zimmermann, J. P. Hill, D. Gibbs, J. C. Woicik, I. Koyama, Y. Murakami. 2000-09-20. X-ray Anomalous Scattering Study of a Charge-Ordered State in NaV2O5. https://doi.org/10.1103/physrevlett.85.4349

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