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Magnetism in disordered graphene and irradiated graphite
1Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Theoretical Physics (ITP), Lausanne, Switzerland. oleg.yazyev@epfl.ch
Physical Review Letters
|September 4, 2008
Summary
Single-atom defects induce ferromagnetism in disordered graphene. Preserved layer stacking is crucial for ferromagnetism in irradiated graphite, confirmed by ab initio calculations.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Physics
Background:
- Graphene and graphite exhibit unique electronic and magnetic properties.
- Understanding magnetism in disordered and irradiated carbon materials is key for advanced applications.
- Defect-induced magnetism is a growing area of research in low-dimensional materials.
Purpose of the Study:
- To systematically investigate the magnetic properties of disordered graphene and irradiated graphite.
- To identify the specific defect types and structural conditions responsible for ferromagnetism.
- To elucidate the role of stacking order in the magnetic behavior of irradiated graphite.
Main Methods:
- Utilizing a combination of the mean-field Hubbard model and first-principles calculations.
- Employing large-scale disordered models to simulate graphene defects.
- Performing ab initio calculations for hydrogen binding, diffusion, and defect recombination.
Main Results:
- Ferromagnetism in graphene-based materials is induced exclusively by single-atom defects.
- A preserved stacking order of graphene layers is a necessary condition for net magnetic moment in irradiated graphite.
- Ab initio calculations confirm the critical role of stacking order in pi-electron ferromagnetism.
Conclusions:
- Single-atom defects are the primary source of ferromagnetism in disordered graphene.
- Maintaining the stacking order of graphene layers is essential for achieving magnetism in irradiated graphite.
- The findings provide fundamental insights into defect-induced magnetism in carbon nanomaterials.
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