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arXiv · 1503.08023

Haydeeite: a spin-1/2 kagome ferromagnet

D. Boldrin·B. Fak·M. Enderle·S. Bieri·J. Ollivier·S. Rols·P. Manuel·A. S. Wills
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Abstract

The mineral haydeeite, alpha-MgCu3(OD)6Cl2, is a S=1/2 kagome ferromagnet that displays long-range magnetic order below TC=4.2 K with a strongly reduced moment. Our inelastic neutron scattering data show clear spin-wave excitations that are well described by a Heisenberg Hamiltonian with ferromagnetic nearest-neighbor exchange J1=-38 K and antiferromagnetic exchange Jd=+11 K across the hexagons of the kagome lattice. These values place haydeeite very close to the quantum phase transition between ferromagnetic order and non-coplanar twelve-sublattice cuboc2 antiferromagnetic order. Diffuse dynamic short-range ferromagnetic correlations observed above TC persist well into the ferromagnetically ordered phase with a behavior distinct from critical scattering.

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D. Boldrin, B. Fak, M. Enderle, S. Bieri, J. Ollivier, S. Rols, P. Manuel, A. S. Wills. 2015-03-27. Haydeeite: a spin-1/2 kagome ferromagnet. https://doi.org/10.1103/physrevb.91.220408

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