Inelastic electron scattering in nickel

Abstract Using a 200 keV electron spectrometer, with an energy resolution of ∼0.25 eV and a momentum resolution of ∼0.2 A -1 , we have measured the energy loss spectra for transmission of electrons through thin (∼600 A) Ni films. These results address the general question of the validity of momentum transfer estimates in electron loss scattering. Using low-energy electron backscattering, we have observed the dipole forbidden M 1 transition at 112 eV. For high-energy scattering, we have observed this transition only at high momentum transfer ( q ⩾ 2 A -1 ). These results indicates sizable contributions from high momentum transfer collisions in the low-energy experiments.