Agrestini S, Borgatti F, Florio P, Frassineti J, Fiore Mosca D, Faure Q, Detlefs B, Sahle C J, Francoual S, Choi J, Garcia-Fernandez M, Zhou K-J, Mitrović V F, Woodward P M, Ghiringhelli G, Franchini C, Boscherini F, Sanna S, Moretti Sala M
<a href="https://ror.org/05etxs293">Diamond Light Source</a>, Harwell Campus, Didcot OX11 0DE, United Kingdom.
<a href="https://ror.org/00w6r1881">Istituto per lo Studio dei Materiali Nanostrutturati</a>, Consiglio Nazionale delle Ricerche (CNR-ISMN), Via P. Gobetti 101, I-40129 Bologna, Italy.
Phys Rev Lett. 2024 Aug 9;133(6):066501. doi: 10.1103/PhysRevLett.133.066501.
A supposedly nonmagnetic 5d^{1} double perovskite oxide is investigated by a combination of spectroscopic and theoretical methods, namely, resonant inelastic x-ray scattering, x-ray absorption spectroscopy, magnetic circular dichroism, and multiplet ligand-field calculations. We found that the large spin-orbit coupling admixes the 5d t_{2g} and e_{g} orbitals, covalency raises the 5d population well above the nominal value, and the local symmetry is lower than O_{h}. The obtained electronic interactions account for the finite magnetic moment of Os in this compound and, in general, of 5d^{1} ions. Our results provide direct evidence of elusive Jahn-Teller distortions, hinting at a strong electron-lattice coupling.
