Low-energy Electron Reflectivity from Graphene
  Low-energy reflectivity of electrons from single- and multi-layer graphene is examined both theoretically and experimentally. A series of minima in the reflectivity over the energy range of 0 - 8 eV are found, with the number of minima depending on the number of graphene layers. Using first-principles computations, it is demonstrated that a free standing n-layer graphene slab produces n-1 reflectivity minima. This same result is also found experimentally for graphene supported on SiO2. For graphene bonded onto other substrates it is argued that a similar series of reflectivity minima is expected, although in certain cases an additional minimum occurs, at an energy that depends on the graphene-substrate separation and the effective potential in that space. 
R. M. Feenstra, N. Srivastava, Qin Gao, M. Widom, Bogdan Diaconescu,   Taisuke Ohta, G. L. Kellogg, J. T. Robinson, I. V. Vl...
cond-mat.mes-hall