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$π$-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism

H. Ohldag·T. Tyliszczak·R. Hoehne·D. Spemann·P. Esquinazi·M. Ungureanu·T. Butz
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Abstract

Elemental carbon represents a fundamental building block of matter and the possibility of ferromagnetic order in carbon attracted widespread attention. However, the origin of magnetic order in such a light element is only poorly understood and has puzzled researchers. We present a spectromicroscopy study at room temperature of proton irradiated metal free carbon using the elemental and chemical specificity of x-ray magnetic circular dichroism (XMCD). We demonstrate that the magnetic order in the investigated system originates only from the carbon $π$-electron system.

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H. Ohldag, T. Tyliszczak, R. Hoehne, D. Spemann, P. Esquinazi, M. Ungureanu, T. Butz. 2007-04-03. $π$-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism. https://doi.org/10.1103/physrevlett.98.187204

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