Oxygen-reduced inner potential and work function in VLEED

Abstract

From the perspective of surface bonding, the origin of the O-reduced inner potential and work function in very LEED (VLEED—very low energy electron diffraction) is analysed. It is recognised that, for the OCu(001) sample, such a reduction originates from the Ometal bonding, namely, variations of atomic states. The inner potential relates to the charge quantity and the work function depends on the density-of-state of the surface. With expansion in size and elevation in energy-state, the metal dipoles induced by the hybridised-O −2 are responsible for the reduction in the local work function. Therefore, the inner potential and the work function act as important identities for the surface electrons. It is suggested that, at very low energies, the exchange-interaction between the energetic incident beams and the surface is insignificant, and hence the energy-reduced inner potential is weak enough to be neglected. The VLEED is therefore an ideal tool for nondestructive information about the behaviour of surface electrons.