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arXiv · 1509.07333

Magnetic behavior of volborthite Cu3V2O7(OH)2(H2O)2 determined by coupled trimers rather than frustrated chains

O. Janson·S. Furukawa·T. Momoi·P. Sindzingre·J. Richter·K. Held
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Abstract

Motivated by recent experiments on volborthite single crystals showing a wide 1/3-magnetization plateau, we perform microscopic modeling by means of density functional theory (DFT) with the single-crystal structural data as a starting point. Using DFT+U, we find four leading magnetic exchanges: antiferromagnetic J and J2, as well as ferromagnetic J' and J1. Simulations of the derived spin Hamiltonian show good agreement with the experimental low-field magnetic susceptibility and high-field magnetization data. The 1/3-plateau phase pertains to polarized magnetic trimers formed by strong J bonds. An effective J$\rightarrow\infty$ model shows a tendency towards condensation of magnon bound states preceding the plateau phase.

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O. Janson, S. Furukawa, T. Momoi, P. Sindzingre, J. Richter, K. Held. 2016-07-13. Magnetic behavior of volborthite Cu3V2O7(OH)2(H2O)2 determined by coupled trimers rather than frustrated chains. https://doi.org/10.1103/physrevlett.117.037206

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