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Charge-Order Pattern of the Low-Temperature Phase of NaV2O5 Uniquely Determined by Resonant X-Ray Scattering from Monoclinic Single Domain

Kenji Ohwada·Yasuhiko Fujii·Yuya Katsuki·Jiro Muraoka·Hironori Nakao·Youichi Murakami·Hiroshi Sawa·Emi Ninomiya·Masahiko Isobe·Yutaka Ueda
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Abstract

The present resonant x-ray scattering from each of monoclinically-split single domains of NaV2O5 has critically enhanced contrast between V4+ and V5+ ions strong enough to lead to unambiguous conclusion of the charge-order pattern of its low-temperature phase below Tc = 35 K. The zig-zag type charge-order patterns in the $ab$-plane previously confirmed have four kinds of configurations (A, A', B and B') and the stacking sequence along the c-axis is determined as the AAA'A' type by comparison with model calculations. By assigning the A and A' configurations to Ising spins, one can reasonably understand the previously discovered "devil's staircase"-type behavior with respect to the modulation of the layer-stacking sequences at high pressures and low temperatures, which very well resembles the global phase diagram theoretically predicted by the ANNNI model.

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Kenji Ohwada, Yasuhiko Fujii, Yuya Katsuki, Jiro Muraoka, Hironori Nakao, Youichi Murakami, Hiroshi Sawa, Emi Ninomiya, Masahiko Isobe, Yutaka Ueda. 2004-08-10. Charge-Order Pattern of the Low-Temperature Phase of NaV2O5 Uniquely Determined by Resonant X-Ray Scattering from Monoclinic Single Domain. https://doi.org/10.1103/physrevlett.94.106401

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