| CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES |
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Electronic Structure of Eu6C60 |
| WANG Xiao-Xiong1,2, LI Hong-Nian1, XU Ya-Bo1, WANG1, ZHANG Wen-Hua3, XU Fa-Qiang3 |
| 1Department of Physics, Zhejiang University, Hangzhou 3100272College of Science, Nanjing University of Science and Technology, Nanjing 2100943National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 |
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| Cite this article: |
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WANG Xiao-Xiong, LI Hong-Nian, XU Ya-Bo et al 2009 Chin. Phys. Lett. 26 017104 |
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Abstract We study the valence band of Eu-intercalated C60 by synchrotron radiation photoelectron spectroscopy to understand the ferromagnetism (FM) and the giant magnetoresistance (GMR) of Eu6C60. The results reveal the semiconducting property and the remarkable 5d6s-π hybridization. Eu-C60 bonding has both ionic and covalent contributions. No more than half the 5d6s electrons transfer from Eu to the LUMO derived band of C60, and the LUMO+1 derived band is not filled. The remaining valence electrons of Eu, together with some π (LUMO, HOMO and HOMO-1) electrons, constitute the covalent bond. The electronic structure implies that the magnetic coupling in Eu6C60 should be through the intra-atomic f-sd exchange and the medium of the π electrons. The possibility of the GMR being tunnelling agnetoresistance is ruled out
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| Keywords:
71.20.Tx
73.20.At
75.50.Dd
75.47.De
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Received: 03 October 2008
Published: 24 December 2008
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| PACS: |
71.20.Tx
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(Fullerenes and related materials; intercalation compounds)
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73.20.At
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(Surface states, band structure, electron density of states)
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75.50.Dd
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(Nonmetallic ferromagnetic materials)
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75.47.De
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(Giant magnetoresistance)
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