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arXiv · 1306.4269

Gapless spin liquid ground state in the S=1/2 vanadium oxyfluoride kagome antiferromagnet [NH4]2[C7H14N][V7O6F18]

L. Clark·J. C. Orain·F. Bert·M. A. de Vries·F. H. Aidoudi·R. E. Morris·P. Lightfoot·J. S. Lord·M. T. F. Telling·P. Bonville·J. P. Attfield·1 P. Mendels·A. Harrison
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Abstract

The vanadium oxyfluoride [NH4]2[C7H14N][V7O6F18] (DQVOF) is a geometrically frustrated magnetic bilayer material. The structure consists of S=1/2 kagome planes of V4+ d1 ions with S=1 V3+ d2 ions located between the kagome layers. Muon spin relaxation measurements demonstrate the absence of spin freezing down to 40 mK despite an energy scale of 60 K for antiferromagnetic exchange interactions. From magnetization and heat capacity measurements we conclude that the S=1 spins of the interplane V3+ ions are weakly coupled to the kagome layers, such that DQVOF can be viewed as an experimental model for S=1/2 kagome physics, and that it displays a gapless spin liquid ground state.

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L. Clark, J. C. Orain, F. Bert, M. A. de Vries, F. H. Aidoudi, R. E. Morris, P. Lightfoot, J. S. Lord, M. T. F. Telling, P. Bonville, J. P. Attfield, 1 P. Mendels, A. Harrison. 2013-06-18. Gapless spin liquid ground state in the S=1/2 vanadium oxyfluoride kagome antiferromagnet [NH4]2[C7H14N][V7O6F18]. https://doi.org/10.1103/physrevlett.110.207208

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