CoIr-carbon complexes with magnetic anisotropies larger than 0.2 eV: A density-functional-theory prediction

We report a density-functional study of the heteronuclear CoIr dimer adsorbed on benzene or graphene. In either case, CoIr prefers an upright position above the center of a carbon hexagon with the Co atom next to it. The Ir atom stays away from the carbon ring and thus preserves its free-atom-like properties. This results in a very large magnetic anisotropy of more than 0.2 eV per dimer. So high a value should suffice for long-term data storage at the temperature of liquid nitrogen.