Enhanced ferromagnetic ordering of a Mn trimer symmetrically and fully exposed on iridium-doped graphene.

The structure and magnetism of a Mn trimer adsorbed on iridium-doped graphene are studied using density functional theory calculations. Our calculation results show that the Mn trimer prefers to locate on top of the Ir atom and forms a fully exposed high-symmetry configuration with large binding energy and hardness of rotation. The ferromagnetic ordering of the Mn trimer fully exposed the on iridium-doped graphene is enhanced five times compared to a free Mn trimer. Our study shows that the enhancement originates from the fixed long bond and the C 3 v symmetry of the Mn trimer constrained by the iridium-doped graphene. [ABSTRACT FROM AUTHOR]