Heavy 5d elements, like osmium, feature strong spin-orbit interactions which are at the origin of exotic physical behaviors. Revealing the full potential of, for example, novel osmium oxide materials (“osmates”) is however contingent upon a detailed understanding of the local single-ion properties. Herein, two molecular osmate analogues, [OsF6]2− and [OsF6]−, are reported as model systems for Os4+ and Os5+ centers found in oxides. Using X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) techniques, combined with state-of-the-art ab initio calculations, their ground state was elucidated; mirroring the osmium electronic structure in osmates. The realization of such molecular model systems provides a unique chemical playground to engineer materials exhibiting spin-orbit entangled phenomena.
Bibliographical noteFunding Information:
The authors thank E. Lebraud, S. Exiga, M. Rouzi?res, and P. Voisin for technical and experimental assistance. The X-ray spectroscopy experiments were performed at the European Synchrotron Radiation Facility (ESRF, Grenoble, France). K.S.P. and R.C. thank the Danish Research Council for Independent Research for a DFF-Sapere Aude Research Talent grant (4090-00201), the University of Bordeaux, the R?gion Nouvelle Aquitaine, the CNRS and the GdR MCM-2: Magn?tisme et Commutation Mol?culaires.
- 5d elements
- X-ray spectroscopy
- ab initio calculations
- spin-orbit interaction