Domain-Wall Spin Dynamics in Kagome Antiferromagnets

Elsa Lhotel (1) , Virginie Simonet (1) , J. Ortloff (2) , Benjamin Canals (3) , Carley Paulsen (1) , E. Suard (4) , T. Hansen (4) , D. J. Price (5) , P. T. Wood (6) , A. K. Powell (7) , Rafik Ballou (1)

1 NEEL - MagSup - Magnétisme et Supraconductivité
2 Institute for Theoretical Physics
3 NEEL - TMC - Théorie de la Matière Condensée
4 ILL - Institut Laue-Langevin
5 WestCHEM
6 Chem Lab
7 KIT - Karlsruhe Institute of Technology

We report magnetization and neutron scattering measurements down to 60 mK on a new family of Fe based kagome antiferromagnets, in which a strong local spin anisotropy combined with a low exchange path network connectivity lead to domain walls intersecting the kagome planes through strings of free spins. These produce unfamiliar slow spin dynamics in the ordered phase, evolving from exchange-released spin flips towards a cooperative behavior on decreasing the temperature, probably due to the onset of long-range dipolar interaction. A domain structure of independent magnetic grains is obtained that could be generic to other frustrated magnets.

Mots clés: Antiferromagnetics; Domain walls and domain structure; Dynamic properties

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

Elsa Lhotel, Virginie Simonet, J. Ortloff, Benjamin Canals, Carley Paulsen, et al.. Domain-Wall Spin Dynamics in Kagome Antiferromagnets. Physical Review Letters, 2011, 107 (25), pp.257205. ⟨10.1103/PHYSREVLETT.107.257205⟩. ⟨hal-00992810⟩