▎ 摘　　要

The graphene/Ni(11 1) system has been studied by angle-resolved electron-energy-loss spectroscopy. The interface-pi plasmon, related to interband transitions involving hybridized states at the K point of the hexagonal Brillouin zone, has been measured at different scattering geometries. The resulting dispersion curve exhibits a square root behavior, indicating the Two-dimensional (2D) character of the interface collective excitation. (C) 2012 Elsevier Ltd. All rights reserved.