  We report the magnitude of the induced magnetic moment in CVD-grown epitaxial
and rotated-domain graphene as a result of the proximity effect in the vicinity
of the ferromagnetic substrates Co and Ni, using polarised neutron reflectivity
(PNR). Although rotated-domain graphene is known to interact weakly with the
ferromagnetic underlayer in comparison with the epitaxial graphene, the PNR
results indicate an induced magnetic moment of $\sim$ 0.57 $\mu_\textrm{B}$/C
atom at 10 K for both structures. The origin of the induced magnetic moment is
found to be due to the opening of the graphene's Dirac cone as a result of the
strong C $p_z-3d$ hybridisation, which was confirmed by additional PNR
measurements using a non-magnetic Ni$_9$Mo$_1$ and Cu substrates. We validated
our PNR fitting models using the Bayesian uncertainty analysis and corroborated
the results by X-ray magnetic circular dichroism measurements.
