The spin-orbit coupling driven spectral and magnetic properties of LiOsO₃: A DFT+DMFT study

Experiments on the 5d-Osmium oxide perovskite LiOsO₃ have revealed surprising physical properties. In contrast to expectations and to the chemically similar material NaOsO₃, LiOsO₃ is never magnetic. Further, its optical properties show a bad metallic behaviour, with a quickly decreasing Drude peak as a function of T [1], as in the 3d-oxide V₂O₃ [2]. A possible origin of this unexpected physics might be the interplay between electronic correlations and spin-orbit coupling (SOC) in this 5d compound. Therefore, we performed a paramagnetic, non SOC dependent DFT and a magnetic DMFT calculation, where we tuned the atomic SOC in the Os t_2g manifold. Without atomic SOC, we find a strong long-range G-type antiferromagnetic order. Turning on atomic SOC antiferromagnetism is gradually suppressed, vanishing at a SOC strength of about 600 meV. This strongly suggests that atomic SOC plays a pivotal role in determining the magnetic properties of osmates.

[1] Lo Vecchio, I. et al. Physical Review B 93, 161113(R) (2016).
[2] Baldassarre, L. et al. Physical Review B 77, 113107 (2008).