Atomic Structure and Quasiparticle Interference of Epitaxial Graphene on Ferromagnetic Mn5Ge3

Abstract The implementation of graphene in spintronics requires the formation of high quality graphene–ferromagnet interfaces for efficient spin injection. By using low‐temperature scanning tunneling microscopy (STM), the atomic structure as well as the electronic properties of epitaxial graphene/ferromagnetic‐Mn5Ge3/semiconducting‐Ge heterostructures are investigated. The formation of the graphene/Mn5Ge3 interface is performed by Mn evaporation on the graphene/Ge(110) surface combined with annealing during and after deposition, yielding graphene on Mn5Ge3 crystallites of two distinct types, each displaying a principal facet – graphene/Mn5Ge3(0001) and graphene/Mn5Ge3(112¯0). STM imaging shows graphene/Mn5Ge3 interfaces with a high degree of structural order down to the atomic level. The local electronic structure of graphene/Mn5Ge3 probed by dI/dV spectroscopy and by quasiparticle interference mapping is found to be very close to that of free‐standing graphene, with only a very small electron doping. These findings provide important microscopic insights into a system with a potential for spintronics device fabrication compatible with modern semiconductor technology.