Effect of magnesium doping on the orbital and magnetic order in LiNiO2

M. Bonda (1) , M. Hopzapfel (1) , Sophie de Brion (2) , Céline Darie (3) , T. Feher (4, 5) , P.J. Baker (6) , T. Lancaster (6) , S.J. Blundell (6) , F.L. Pratt (7)

1 LCMI-GHMFL - Laboratoire des champs magnétiques intenses
2 NEEL - MagSup - Magnétisme et Supraconductivité
3 NEEL - MRS - Matériaux, Rayonnements, Structure
4 Condensed Matter Physics Group of the Hungarian Academy of Science and Department of Physics
5 EPFL - Ecole Polytechnique Fédérale de Lausanne
6 Clarendon Laboratory [Oxford]
7 ISIS Muon Facility

In LiNiO2, the Ni3+ ions, with S=1/2 and twofold orbital degeneracy, are arranged on a trian- gular lattice. Using muon spin relaxation (MuSR) and electron spin resonance (ESR), we show that magnesium doping does not stabilize any magnetic or orbital order, despite the absence of interplane Ni2+. A disordered, slowly fluctuating state develops below 12 K. In addition, we find that magnons are excited on the time scale of the ESR experiment. At the same time, a g factor anisotropy is observed, in agreement with $\vert 3z^{2}-r^{2}\rangle$ orbital occupancy.

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

M. Bonda, M. Hopzapfel, Sophie de Brion, Céline Darie, T. Feher, et al.. Effect of magnesium doping on the orbital and magnetic order in LiNiO2. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008, 78 (10), pp.104409. ⟨10.1103/PhysRevB.78.104409⟩. ⟨hal-00307869⟩