Ferromagnetic Boundary States in the Hydrogenated Graphene/Nickel Moiré Superlattice

Zigzag graphene nanoribbons (ZGNRs) exhibit spin-polarized edge states, which are key elements for designing graphene-based spintronics devices. The intrinsic ZGNRs have an antiferromagnetic ground state, which can be modified by edge engineering and external field. Here, this work proposes an avenue to realize the zigzag graphene/graphane nanoribbon superlattice (ZGNR-SL) on Ni(100) by selective hydrogenation of the 1D moiré patterns, based on the first-principles calculations. The growth mechanism of the ZGNR-SL is revealed having two steps: first, hydrogen atoms intercalate at the interface of graphene/Ni and form H ribbons in the apex regions of the 1D moiré pattern; second, the intercalated hydrogen ribbons serve as a template for the directed hydrogen adsorption on both sides of the graphene over the hydrogen ribbons. Interestingly, ZGNR-SL on Ni(100) surface exhibit ferromagnetic boundary states, which may be exploited in potential spintronics device applications.