  We demonstrate that freeing a single-atom thick layer of hexagonal boron
nitride (hbn) from tight chemical bonding to a Ni(111) thin film grown on a
W(110) substrate can be achieved by intercalation of Au atoms into the
interface. This process has been systematically investigated using
angle-resolved photoemission spectroscopy, X-ray photoemission and absorption
techniques. It has been demonstrated that the transition of the hbn layer from
the "rigid" into the "quasi-freestanding" state is accompanied by a change of
its lattice constant. Using chemical vapor deposition, graphene has been
successfully synthesized on the insulating, quasi-freestanding hbn monolayer.
We anticipate that the in situ synthesized weakly interacting graphene/hbn
double layered system could be further developed for technological applications
and may provide perspectives for further inquiry into the unusual electronic
properties of graphene.
