• 文献标题:   Origin of Room-Temperature Ferromagnetism in Hydrogenated Epitaxial Graphene on Silicon Carbide
  • 文献类型:   Article
  • 作  者:   RIDENE M, NAJAFI A, FLIPSE K
  • 作者关键词:   hydrogenated epitaxial graphene, electronic structure, ferromagnetism
  • 出版物名称:   NANOMATERIALS
  • ISSN:  
  • 通讯作者地址:   Eindhoven Univ Technol
  • 被引频次:   0
  • DOI:   10.3390/nano9020228
  • 出版年:   2019

▎ 摘  要

The discovery of room-temperature ferromagnetism of hydrogenated epitaxial graphene on silicon carbide challenges for a fundamental understanding of this long-range phenomenon. Carbon allotropes with their dispersive electron states at the Fermi level and a small spin-orbit coupling are not an obvious candidate for ferromagnetism. Here we show that the origin of ferromagnetism in hydrogenated epitaxial graphene with a relatively high Curie temperature (>300 K) lies in the formation of curved specific carbon site regions in the graphene layer, induced by the underlying Si-dangling bonds and by the hydrogen bonding. Hydrogen adsorption is therefore more favourable at only one sublattice site, resulting in a localized state at the Fermi energy that can be attributed to a pseudo-Landau level splitting. This n = 0 level forms a spin-polarized narrow band at the Fermi energy leading to a high Curie temperature and larger magnetic moment can be achieved due to the presence of Si dangling bonds underneath the hydrogenated graphene layer.