title: Preserving the edge magnetism of zigzag graphene nanoribbons by ethylene termination: insight by Clar's rule.
abstract: By means of density functional theory computations, we demonstrated that C2H4 is the ideal terminal group for zigzag graphene nanoribbons (zGNRs) in terms of preserving the edge magnetism with experimental feasibility. The C2H4 terminated zGNRs (C2H4-zGNRs) with pure sp(2) coordinated edges can be stabilized at rather mild experimental conditions, and meanwhile reproduce the electronic and magnetic properties of those hydrogen terminated zGNRs. Interestingly, the electronic structures and relative stability of C2H4-zGNRs with different edge configurations can be well interpreted by employing the Clar's rule. The multiple edge hyperconjugation interactions are responsible for the enhanced stability of the sp(2) coordinated edges of C2H4-zGNRs. Moreover, we demonstrated that even pure sp(2) termination is not a guarantee for edge magnetism, for example, C2H2 termination can couple to the π-electron system of zGNRs, and destroy the magnetism. Our studies would pave the way for the application of zGNRs in spintronics.
authors.affiliation: Department of Chemistry, Institute for Functional Nanomaterials, NASA-URC Center for Advanced Nanoscale Materials, University of Puerto Rico, Rio Piedras Campus, San Juan, PR 00931.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhou
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Cabrera
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Chen