Strong covalent bonding between two graphene layers

We show that two graphene layers stacked directly on top of each other (AA stacking) form strong chemical bonds when the distance between planes is 0.156 nm. Simultaneously, C-C in-plane bonds are considerably weakened from partial double-bond (0.141 nm) to single bond (0.154 nm). This polymorphic f...

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Detalhes bibliográficos
Autores: Andrés, Pedro L. de, Ramírez, Rafael, Vergés, José A.
Tipo de documento: artigo
Data de publicação:2008
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/2757
Acesso em linha:http://hdl.handle.net/10261/2757
Access Level:Acceso aberto
Palavra-chave:few graphene layers
Descrição
Resumo:We show that two graphene layers stacked directly on top of each other (AA stacking) form strong chemical bonds when the distance between planes is 0.156 nm. Simultaneously, C-C in-plane bonds are considerably weakened from partial double-bond (0.141 nm) to single bond (0.154 nm). This polymorphic form of graphene bilayer is meta-stable w.r.t. the one bound by van der Waals forces at a larger separation (0.335 nm) with an activation energy of 0.16 eV/cell. Similarly to the structure found in hexaprismane, C forms four single bonds in a geometry mixing 90 and 120 angles. Intermediate separations between layers can be stabilized under external anisotropic stresses showing a rich electronic structure changing from semi-metal at van der Waals distance, to metal when compressed, to wide gap semiconductor at the meta-stable minimum.

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