New publicaton in Nature Communications

Post date: Oct 27, 2016 1:24:34 PM

Iridates from the molecular side

The intrinsic electronic characteristics of the paramagnetic Ir⁴⁺ ion in “iridates”, including the 5d spin and orbital moments, as well as its magnetization dynamics have been quantified, thanks to the synthesis, and structural, spectroscopic and magnetic characterization of [IrF₆]^2--based fluorido-iridate analogues. These results appeared recently in Nature Communications [7:12195]. This work was realized through a scientific cooperation between two research groups of the ICMCB-CNRS, “Chemistry and photonic of oxide and fluoride materials” and “Switchable Molecules and Materials”, and the “Molecular Materials & Magnetism” team at the CRPP-CNRS. Several other French and European laboratories were associated to this detailed study including the University of Copenhagen, the Institut Néel and ESRF in Grenoble, the Paul Scherrer Institute in Switzerland, the University of Oxford in UK and the Academy of Sciences of Moldova.

The exotic electronic properties of the iridates originate from the paramagnetic Ir⁴⁺ ion and the concerted effects of the crystal field, magnetic interactions and the strong spin-orbit coupling characteristic of the 5d metal ions. The use of fluorination techniques combined with soft chemistry routes has allowed the synthesis of Ir⁴⁺-based fluoro-iridates, such as (PPh₄)₂[IrF₆]•2H₂O, with PPh₄ = tetraphenylphosphonium(V) cation, isoelectronic to its oxide-analogues. These molecular compounds emerge as ideal model systems for oxo-iridate materials, since [IrF₆]^2- moieties are electronically and magnetically isolated, thus lifting the disturbing long-range interactions. These results may open perspectives for using fluorido-iridates as building-blocks for electronic and magnetic quantum materials, through soft chemistry routes.

For more information, see the CNRS press release: En direct des laboratoires de l'institut de Chimie