Anisotropic interactions opposing magnetocrystalline anisotropy in Sr3NiIrO6

E. Lefrançois (1) , A.-M. Pradipto (2) , M. Moretti Sala (3) , L. Chapon (4) , V. Simonet (1) , S. Picozzi (2) , P. Lejay (5) , S. Petit (6) , R. Ballou (1)

1 NEEL - MagSup - Magnétisme et Supraconductivité
2 SPIN - Istituto Superconduttori, Materiali Innovativi e Dispositivi
3 POLIMI - Politecnico di Milano [Milan]
4 ILL - Institut Laue-Langevin
5 NEEL - C2MA - Croissance Cristalline et MicroAnalyse
6 LLB - UMR 12 - Laboratoire Léon Brillouin

We report our investigation of the electronic and magnetic excitations of Sr3NiIrO6 by resonant inelastic x-ray scattering at the Ir L3 edge. The intra-t2g electronic transitions are analyzed using an atomic model, including spin-orbit coupling and trigonal distortion of the IrO6 octahedron, confronted to ab initio quantum chemistry calculations. The Ir spin-orbital entanglement is quantified and its implication on the magnetic properties, in particular in inducing highly anisotropic magnetic interactions, is highlighted. These are included in the spin-wave model proposed to account for the dispersionless magnetic excitation that we observe at 90 meV. By counterbalancing the strong Ni2+ easy-plane anisotropy that manifests itself at high temperature, the anisotropy of the interactions finally leads to the remarkable easy-axis magnetism reported in this material at low temperature.

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

E. Lefrançois, A.-M. Pradipto, M. Moretti Sala, L. Chapon, V. Simonet, et al.. Anisotropic interactions opposing magnetocrystalline anisotropy in Sr3NiIrO6. Physical Review B, 2016, 93 (22), pp.224401. ⟨10.1103/PhysRevB.93.224401⟩. ⟨hal-01947536⟩