Abstract: Complexes with a strong spin-orbit interaction have attracted much attention in recent years due to their electrical and magnetic properties, such as superconductivity, magnetic ordering at high temperatures, anomalous and spin Hall effects, and the Rashba effect. The complexes (NH4)2[OsCl6], [M(NH3)4][OsCl6] (M = Pd, Pt) and [ Co(NH3)5Cl][OsCl6] were studied to estimate the effect of spin-orbit interactions on the electronic structure and magnetic properties. The octahedral anions {OsCl6}2- are isolated centers and therefore do not participate in the superexchange interaction, which made it possible to study the correlations between the structure and spin-orbit interaction. OsCl3 and OsCl4 compounds were also studied, in which Os-Cl-Os bridging bonds are formed, which leads to the appearance of exchange interactions. X-ray emission spectroscopy and X-ray absorption spectroscopy are sensitive methods to study changes in the electronic structure. The XANES Cl K- and X-ray emission Cl Kβ spectra of the complexes (NH4)2[OsCl6], [M(NH3)4][OsCl6] (M = Pd, Pt) and [Co(NH3)5Cl][OsCl6] and chain compounds OsCl3 and OsCl4 were obtained. Quantum-chemical calculations were carried out using the multiconfigurational CASSCF method to interpret the obtained spectra. The combined use of experimental X-ray and theoretical methods made it possible to determine the magnitude of the spin-orbit interaction depending on the cation substitution and to estimate the influence of the parameters of the electronic structure (crystal field and interelectron repulsion, spin-orbit interaction constants) on the magnetic properties and the structure of X-ray spectra. The work was supported by the Russian Science Foundation (project 22-22-00683).

Cite: Fedorenko A.D. , Asanov I.P. , Nedoseikina T.I. , Nikolenko A.D.
Features of XANES Cl K- and X-ray Emission Cl Kβ Spectra of {OsCl6}2- Compounds with a Strong Spin-Orbit Interaction Depending on the Structure of Cations
International Conference "Synchrotron and Free electron laser Radiation: generation and application" 27-30 Jun 2022