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arXiv · 0906.2846

Phase Diagram and Spin Dynamics in Volborthite with a Distorted Kagome Lattice

M. Yoshida·M. Takigawa·H. Yoshida·Y. Okamoto·Z. Hiroi
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Abstract

We report 51V-NMR study on a high-quality powder sample of volborthite Cu3V2O7(OH)2/2H2O, a spin-1/2 Heisenberg antiferromagnet on a distorted kagome lattice formed by isosceles triangles. In the magnetic fields below 4.5 T, a sharp peak in the nuclear spin-lattice relaxation rate 1/T1 accompanied with line broadening revealed a magnetic transition near 1 K. The low temperature phase shows anomalies such as a Lorentzian line shape, a 1/T1 propto T behavior indicating dense low energy excitations, and a large spin-echo decay rate 1/T2 pointing to unusually slow fluctuations. Another magnetic phase appears above 4.5 T with less anomalous spectral shape and dynamics.

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M. Yoshida, M. Takigawa, H. Yoshida, Y. Okamoto, Z. Hiroi. 2009-06-16. Phase Diagram and Spin Dynamics in Volborthite with a Distorted Kagome Lattice. https://doi.org/10.1103/physrevlett.103.077207

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