Intricacies of the Co${}^{3+}$ spin state in Sr${}_2$Co${}_{0.5}$Ir${}_{0.5}$O${}_4$: an x-ray absorption and magnetic circular dichroism study

Abstract

We report on a combined soft x-ray absorption and magnetic circular dichroism (XMCD) study at the Co-$L_{3,2}$ on the hybrid 3$d$/5$d$ solid state oxide Sr${}_2$Co${}_{0.5}$Ir${}_{0.5}$O${}_4$ with the K${}_2$NiF${}_4$ structure. Our data indicate unambiguously a pure high spin state $(S=2)$ for the Co${}^{3+}$ (3$d^6$) ions with a significant unquenched orbital moment $L_z/2S_z=0.25$ despite the sizeable elongation of the CoO${}_6$ octahedra. Using quantitative model calculations based on parameters consistent with our spectra, we have investigated the stability of this high spin state with respect to the competing low spin and intermediate spin states.

arXiv comment7 pages, 4 figures

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Cited by in corpus (4)

• Probing the $J_{eff}=0$ ground state and the Van Vleck paramagnetism of the Ir${}^{5+}$ ions in the layered Sr${}_2$Co${}_{0.5}$Ir${}_{0.5}$O${}_4$
• Strain induced changes of electronic properties of B-site ordered double perovskite Sr${}_2$CoIrO${}_6$ thin films
• Negative charge transfer energy in correlated compounds
• Crystal structure and properties of iron-based spin-chain compound Ba9Fe3Se15