Study of the intercalation of graphene on Ni(111) with Cs atoms: Towards the quasi-free graphene

In this work we present an experimental study of the intercalation of the graphene/Ni(111) system by cesium atoms. The evidence of a complete alkali intercalation has been obtained by Auger and angle-resolved electron-energy-loss measurements. The changes in the electronic and vibrational properties demonstrate that a weakly bonded graphene layer can be synthesized on Ni(111) by means of Cs intercalation. - Highlights: • A complete intercalation of graphene/Ni(111) system by Cs atoms has been obtained. • From graphene/Ni(111) to graphene/Cs/Ni(111): EELS evidences • Intercalation of Cs atoms makes the epitaxial graphene on Ni(111) quasi-free