| Autor: |
Agrestini, S., Chen, K., Kuo, C. -Y., Zhao, L., Lin, H. -J., Chen, C. -T., Rogalev, A., Ohresser, P., Chan, T. -S., Weng, S. -C., Komarek, A. C., Yamaura, K., Haverkort, M. W., Hu, Z., Tjeng, L. H. |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Phys. Rev. B 100, 014443 (2019) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.100.014443 |
| Popis: |
We report on our investigation on the magnetism of the iridate double perovskite Sr$_2$CoIrO$_6$, a nominally Ir$^{5+}$ Van Vleck $J_{eff}=0$ system. Using x-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectroscopy at the Ir-$L_{2,3}$ edges, we found a nearly zero orbital contribution to the magnetic moment and thus an apparent breakdown of the $J_{eff}=0$ ground state. By carrying out also XAS and XMCD experiments at the Co-$L_{2,3}$ edges and by performing detailed full atomic multiplet calculations to simulate all spectra, we discovered that the compound consists of about 90% Ir$^{5+}$ ($J_{eff}=0$) and Co$^{3+}$ ($S=2$) and 10% Ir$^{6+}$ ($S=3/2$) and Co$^{2+}$ ($S=3/2$). The magnetic signal of this minority Ir$^{6+}$ component is almost equally strong as that of the main Ir$^{5+}$ component. We infer that there is a competition between the Ir$^{5+}$-Co$^{3+}$ and the Ir$^{6+}$-Co$^{2+}$ configurations in this stoichiometric compound. |
| Databáze: |
arXiv |
| Externí odkaz: |
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