Dynamics in pure and substituted volborthite kagome-like compounds

F. Bert (1) , P. Mendels (1) , D. Bono (1) , A. Olariu (1) , F. Ladieu (2) , J.-C. Trombe (3) , F. Duc (3) , C. Baines (4) , A. Amato (4) , A. Hillier (5)

1 LPS - Laboratoire de Physique des Solides
2 SPEC - UMR3680 - Service de physique de l'état condensé
3 CEMES - Centre d'élaboration de matériaux et d'études structurales
4 PSI - Paul Scherrer Institute
5 ISIS Facility

Volborthite Cu 3 V 2 O 7 ðOHÞ 2 Á 2H 2 O is a natural frustrated antiferromagnet with a kagome´-kagome´-like magnetic lattice decorated by S ¼ 1 2 spins. Our mSR results confirm the existence of a dynamical plateau below 2 K, as initially demonstrated in [Phys. Rev. Lett. 91 (2003) 207603] despite sensible quantitative differences in the relaxation rate values. Thanks to additional low temperature SQUID and NMR data we show that this plateau occurs concurrently with a freezing transition. Moreover, we revisited the effect of diluting the magnetic lattice for small dilution rates between 1% and 15%. Comparison is made with the well studied kagome´bilayerkagome´bilayer compounds. The ground state of volborthite appears to be far less stable with respect to dilution.

Keywords: Muon-spin rotation; Kagome´ lattice; Frustrated magnets

Domains: Physics [physics]

F. Bert, P. Mendels, D. Bono, A. Olariu, F. Ladieu, et al.. Dynamics in pure and substituted volborthite kagome-like compounds. Physica B: Condensed Matter, 2006, 374, pp.134 - 137. ⟨10.1016/j.physb.2005.11.034⟩. ⟨cea-01396624⟩