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arXiv · 1504.05420

Anisotropic interactions opposing magnetocrystalline anisotropy in Sr$_3$NiIrO$_6$

E. Lefrançois·A. -M. Pradipto·M. Moretti Sala·L. C. Chapon·V. Simonet·S. Picozzi·P. Lejay·S. Petit·R. Ballou
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Abstract

We report our investigation of the electronic and magnetic excitations of Sr$_3$NiIrO$_6$ by resonant inelastic x-ray scattering at the Ir L$_3$ edge. The intra-$t_{2g}$ electronic transitions are analyzed using an atomic model, including spin-orbit coupling and trigonal distortion of the IrO$_6$ octahedron, confronted to {\it 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 Ni$^{2+}$ 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.

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E. Lefrançois, A. -M. Pradipto, M. Moretti Sala, L. C. Chapon, V. Simonet, S. Picozzi, P. Lejay, S. Petit, R. Ballou. 2016-04-13. Anisotropic interactions opposing magnetocrystalline anisotropy in Sr$_3$NiIrO$_6$. https://doi.org/10.1103/physrevb.93.224401

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