Local electronic structure of Fe2+ impurities in MgO thin films: temperature-dependent soft x-ray absorption spectroscopy study
We report on the local electronic structure of Fe impurities in MgO thin films. Using soft x-ray absorption spectroscopy (XAS) we verified that the Fe impurities are all in the 2+ valence state. The fine details in the line shape of the Fe $L_{2,3}$ edges provide direct evidence for the presence of...
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| Main Authors: | , |
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| Format: | Article (Journal) Chapter/Article |
| Language: | English |
| Published: |
2010
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| In: |
Arxiv
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| Online Access: | Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1011.1152
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| Author Notes: | T. Haupricht, R. Sutarto, M.W. Haverkort, H. Ott, A. Tanaka, H.H. Hsieh, H.-J. Lin, C.T. Chen, Z. Hu, and L.H. Tjeng |
| Summary: | We report on the local electronic structure of Fe impurities in MgO thin films. Using soft x-ray absorption spectroscopy (XAS) we verified that the Fe impurities are all in the 2+ valence state. The fine details in the line shape of the Fe $L_{2,3}$ edges provide direct evidence for the presence of a dynamical Jahn-Teller distortion. We are able to determine the magnitude of the effective $D_{4h}$ crystal field energies. We also observed a strong temperature dependence in the spectra which we can attribute to the thermal population of low-lying excited states that are present due to the spin-orbit coupling in the Fe 3d. Using this Fe$^{2+}$ impurity system as an example, we show that an accurate measurement of the orbital moment in Fe$_3$O$_4$ will provide a direct estimate for the effective local low-symmetry crystal fields on the Fe$^{2+}$ sites, important for the theoretical modeling of the formation of orbital ordering. |
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| Item Description: | Die Ziffer 2 sowie das +Zeichen im Titel sind hochgestellt Gesehen am 27.11.2017 |
| Physical Description: | Online Resource |