Vesignieite: a S = (1)/(2) kagome antiferromagnet with dominant third-neighbor exchange

2018/06/08 by D. Boldrin, B. Fåk, E. Canévet +5 · 1 citation
Physics and Astronomy · #cond-mat.str-el

paper · pdf · doi:10.1103/physrevlett.121.107203

published as Phys. Rev. Lett. 121, 107203 (2018)

arxiv created 2018/06/08 · arxiv updated 2018/09/12

Abstract

The spin-(1)/(2) kagome antiferromagnet is an archetypal frustrated system predicted to host a variety of exotic magnetic states. We show using neutron scattering measurements that deuterated vesignieite BaCu₃V₂O₈(OD)₂, a fully stoichiometric S=1/2 kagome magnet with <1% lattice distortion, orders magnetically at T_N=9K into a multi-k coplanar variant of the predicted triple-k octahedral structure. We find this structure is stabilized by a dominant antiferromagnetic 3^rd-neighbor exchange J₃ with minor 1^st- or 2^nd--neighbour exchange. The spin-wave spectrum is well described by a J₃-only model including a tiny symmetric exchange anisotropy.

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