  We investigate a well defined heterostructure constituted by magnetic Fe
layers sandwiched between graphene (Gr) and Ir(111). The challenging task to
avoid Fe-C solubility and Fe-Ir intermixing has been achieved with atomic
controlled Fe intercalation at moderate temperature below 500 K. Upon
intercalation of a single ordered Fe layer in registry with the Ir substrate,
an intermixing of the Gr bands and Fe d states breaks the symmetry of the Dirac
cone, with a downshift in energy of the apex by about 3 eV, and well-localized
Fe intermixed states induced in the energy region just below the Fermi level.
First principles electronic structure calculations show a large spin splitting
of the Fe states, resulting in a majority spin channel almost fully occupied
and strongly hybridized with Gr {\pi} states. X-ray magnetic circular dichroism
on the Gr/Fe/Ir heterostructure reveals an ordered spin configuration with a
ferromagnetic response of Fe layer(s), with enhanced spin and orbital
configurations with respect to the bcc-Fe bulk values. The magnetization
switches from a perpendicular easy magnetization axis when the Fe single layer
is lattice matched with the Ir(111) surface to a parallel one when the Fe thin
film is almost commensurate with graphene.
