Europium intercalation as a route to modulate electronic and magnetic properties of h-BN/Ni(111)

We present a combined density functional theory (DFT) and photoelectron spectroscopy (PES) study of the electronic and magnetic properties of the intercalation-like system, where europium (Eu) is intercalated at the interface between hexagonal boron nitride (h-BN) and a Ni(111) substrate. From the theory side two interface models are considered: (i) a sharp h-BN/Eu/Ni(111) structure and (ii) an interfacial EuNi₅ alloy. In both cases, Eu intercalation restores the π-band dispersion of h-BN and induces doping effects, with the energy shift of the π-band at the Γ point found to be highly sensitive to the interfacial structure. Our results show that Eu retains a localized magnetic moment in both configurations, with distinct coupling to the substrate. Simulated B 1s and N 1s core-level shifts and near-edge X-ray absorption spectra provide further insights into the local bonding environment and interfacial interaction strength. Further systematic electron diffraction and PES experiments support the formation of the sharp h-BN/Eu/Ni(111) interface as derived from the matching of experimentally derived positions of B 1s and N 1s core-levels as well as valence bands dispersions to the theoretical results. These findings offer a framework for understanding the role of rare-earth intercalation in tuning the properties of 2D/metal interfaces and pave the way for future spintronic applications.