1305.5978 (Jun Hu et al.)

Giant magnetic anisotropy of transition-metal dimers on defected
graphene from the first-principles calculations    [PDF]

Jun Hu, Ruqian Wu

The demanding of miniaturizing magnetic devices drives the efforts to search for magnetic nanostructures with large magnetic anisotropy energy (MAE). Although a various of nanostructures such molecular magnets, magnetic nanoclusters and nanowires have been proposed to be potential magnetic building blocks, the blocking temperature for the fluctuation of magnetization is typically lower than 50 K due to the small MAEs of the magnetic materials. Through density functional theory calculations, we demonstrated the possibility of achieving giant MAE in systems with transition-metal dimers on defected and decorated graphene. In particular, either Pt-Ir dimer on a single vacancy or Os-Ru dimer on a nitrogen-decorated divacancy possesses an MAE larger than 60 meV and has high structural stability against diffusion and dissociation. The underlying mechanism of the giant MAEs was discussed, and we further propose possible means such as using external electric field to manipulate the magnetic anisotropy in these systems. This paves the way for the development of nanoscale spintronics devices for the use in ambient condition.

View original: http://arxiv.org/abs/1305.5978