Realization of a New Graphene-Ferromagnet Interface with Dirac Linear Band Dispersion

The integration of graphene in spintronics applications requires its close contact with ferromagnetic materials, promoting effective spin injection. At the same time, the linear energy vs wave-vector dependence for the charge carriers in the vicinity of the Fermi level for graphene has to be conserved. Here, motivated by recent theoretical predictions, we present the experimental realization on the synthesis of graphene/ferromagnetic-Mn₅Ge₃/semiconducting-Ge heterostructures using the intercalation of Mn in the epitaxial graphene/Ge interfaces. Different in situ and ex situ methods confirm the formation of such heterosystems, where graphene is in close contact with ferromagnetic Mn₅Ge₃, as the Curie temperature reaches room temperature. Despite the expected small distance between graphene and Mn₅Ge₃ causing the strong interaction at interfaces, our angle-resolved photoelectron spectroscopy experiments for the formed graphene/Mn₅Ge₃ interfaces confirm the linear band dispersion around the Fermi level for the carriers in graphene. These findings open up an interesting perspective for the integration of graphene in modern semiconductor technology with possible implications for spintronics device fabrication.