Magnetic excitations in a new anisotropic Kagomé antiferromagnet

Julien Robert (1) , Virginie Simonet (1) , Benjamin Canals (1) , Rafik Ballou (1) , Pierre Bordet (2) , Isabelle Gelard (2) , Alain Ibanez (2) , Pascal Lejay (3) , Jacques Ollivier (4) , Anne Stunault (4)

1 LLN - Laboratoire Louis Néel
2 Laboratoire de Cristallographie
3 CRTBT - Centre de Recherches sur les Très Basses Températures
4 ILL - Institut Laue-Langevin

The Nd-langasite compound contains planes of magnetic Nd3+ ions on a lattice topologically equivalent to a kagomé net. The magnetic susceptibility does not reveal any signature of long-range ordering down to 2 K but rather a correlated paramagnetism with significant antiferromagnetic interactions between the Nd and a single-ion anisotropy due to crystal field effect. Inelastic neutron scattering on Nd-langasite powder and single-crystal allowed to probe its very peculiar low temperature dynamical magnetic correlations. They present unusual dispersive features and are broadly localized in wave-vector Q revealing a structure factor associated to characteristics short range-correlations between the magnetic atoms. From comparison with theoretical calculations, these results are interpreted as a possible experimental observation of a spin liquid state in an anisotropic kagomé antiferromagnet.

Mots clés: kagomé; spin liquid; inelastic neutron scattering; magnetic anisotropy

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Julien Robert, Virginie Simonet, Benjamin Canals, Rafik Ballou, Pierre Bordet, et al.. Magnetic excitations in a new anisotropic Kagomé antiferromagnet. 2006. ⟨hal-00068174⟩