• 文献标题:   Structure and magnetic properties of curved graphene networks and the effects of bromine and potassium adsorption
  • 文献类型:   Article
  • 作  者:   TAKAI K, SUZUKI T, ENOKI T, NISHIHARA H, KYOTANI T
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Tokyo Inst Technol
  • 被引频次:   19
  • DOI:   10.1103/PhysRevB.81.205420
  • 出版年:   2010

▎ 摘  要

The structure and magnetic properties of nanoporous zeolite-templated carbon (ZTC) and its guest-adsorbed systems are investigated using potassium and bromine as guest species. In ZTC, nanopores formed by a three-dimensional curved-graphene network, whose structure is transcribed from the zeolite nanopore structure, are regularly arranged (periodicity: 1.4 nm). The regularity of the nanopore structure is preserved during vacuum heat treatment (<380 degrees C) and potassium adsorption, though it is destroyed by bromine adsorption. The pristine ZTC has localized spins, whose origin is attributed to those created in the region having a negative curvature in the graphene network, as well as to the contribution of an edge state. The spin concentration is estimated as 1 spin/nanopore and is independent of the heat-treatment temperature up to 380 degrees C. In potassium-adsorbed ZTC, potassium atoms forming networked clusters in the nanopores are magnetic and undergo a weak ferromagnetic transition at 24 K. The ZTC spins, which are not directly coupled with the potassium spins through exchange interaction, accurately mirror the magnetic behavior of the potassium spins.