Soft x-ray magnetic circular dichroism of LaCoO$_{3}$, La$_{0.7}$Ce$_{0.3}$CoO$_{3}$, and La$_{0.7}$Sr$_{0.3}$CoO$_{3}$ films: Evidence for Co valency-dependent magnetism and magnetic anisotropy
| Autor: | Merz, M., Nagel, P., Pinta, C., Samartsev, A., Loehneysen, H. v., Wissinger, M., Uebe, S., Assmann, A., Fuchs, D., Schuppler, S. |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Physical Review B 82, 174416 (2010) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.82.174416 |
| Popis: | Epitaxial thin films of undoped LaCoO$_{3}$\@, of electron-doped La$_{0.7}$Ce$_{0.3}$CoO$_{3}$\@, and of hole-doped La$_{0.7}$Sr$_{0.3}$CoO$_{3}$\@ exhibit ferromagnetic order with a transition temperature $T_{\rm{C}}$ $\approx$ 85 K, 22 K, and 240 K, respectively. The spin-state structure for these compounds was studied by soft x-ray magnetic circular dichroism at the Co $L_{2,3}$ and O $K$ edges. It turns out that a higher spin state of the Co$^{3+}$ ions is responsible for the magnetism in LaCoO$_{3}$\@ while for La$_{0.7}$Ce$_{0.3}$CoO$_{3}$ the Co$^{3+}$ ions are in a low-spin state and the ferromagnetism is predominantly determined by Co$^{2+}$\@. For La$_{0.7}$Sr$_{0.3}$CoO$_{3}$\@, on the other hand, the magnetism originates from higher spin states of Co$^{3+}$ and Co$^{4+}$\@. Moreover, a strong magnetic anisotropy is observed for all systems. Comment: submitted |
| Databáze: | arXiv |
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