Vesignieite BaCu3V2O8(OH)2 as a Candidate Spin-1/2 Kagome Antiferromagnet

TL;DR

This study synthesizes and investigates vesignieite, a nearly ideal spin-1/2 kagome antiferromagnet, revealing no magnetic order down to 2 K and suggesting a possible gapless spin liquid ground state.

Contribution

It provides experimental evidence of a nearly ideal kagome lattice with no magnetic order, supporting the candidate status of vesignieite as a spin liquid.

Findings

No long-range magnetic order observed down to 2 K

Presence of a broad peak indicating short-range order

Possible gapless spin liquid ground state

Abstract

A polycrystalline sample of vesignieite BaCu3V2O8(OH)2 comprising a nearly ideal kagome lattice composed of Cu2+ ions carrying spin 1/2 has been synthesized and studied by magnetization and heat capacity measurements. Magnetic susceptibility shows a neither long range order, a spin glass transition nor a spin gap down to 2 K, in spite of a moderately strong antiferromagnetic interaction of J/kB = 53 K between nearest-neighbor spins. A broad peak observed at a temperature corresponding to 0.4J in intrinsic magnetic susceptibility indicates a marked development of the short-range order. The ground state of vesignieite is probably a gapless spin liquid or is accompanied by a very small gap less than J/30.