Magnetic properties of a family of quinternary oxalates

Elsa Lhotel (1) , Virginie Simonet (1) , J. Ortloff (2) , Benjamin Canals (3) , Carley Paulsen (1) , E. Suard , T. Hansen (4) , D. J. Price (5) , P. T. Wood (6) , A. K. Powell (7, 8) , 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 INSTITUT FüR ANORGANISHE CHEMIE - Institut für Anorganishe Chemie
8 Institute for Nanotechnology

We report on the magnetic properties of four isomorphous compounds of a family of quinternary oxalates down to 60 mK. In all these materials, the magnetic FeII ions with a strong magneto-crystalline anisotropy form a distorted kagome lattice, topologically equivalent to a perfect kagome one if nearest-neighbor interactions only are considered. All the compounds order at low temperature in an antiferromagnetic arrangement with magnetic moments at 120°. A remarkable magnetic behavior emerges below the Néel temperature in three compounds (with inter-kagome-layer Zr, Sn, Fe but not with Al): the 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 an unfamiliar slow spin dynamics in the ordered phase observed by AC susceptibility, evolving from exchange-released spin-flips towards a cooperative behavior on decreasing the temperature.

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

Elsa Lhotel, Virginie Simonet, J. Ortloff, Benjamin Canals, Carley Paulsen, et al.. Magnetic properties of a family of quinternary oxalates. The European Physical Journal B: Condensed Matter and Complex Systems, 2013, 86, pp.248. ⟨10.1140/EPJB/E2013-30668-4⟩. ⟨hal-00992804⟩