Impact collision ion scattering spectroscopy (ICISS) and neutral impact collision ion scattering spectroscopy (NICISS) at surfaces of organic liquids

NICISS and ICISS in the low energy regime (1-5 keV) with helium as a projectile is used to investigate surfaces of organic liquids. We determine qualitatively the composition of the outermost layer with ICISS. The composition of the bulk near to the surface is determined quantitatively with NICISS up to a depth of several 10 Angstrom. The additional loss of energy of the projectiles by low angle scattering and electronic excitation (stopping power) is used to determine the depth of the target atom. We have investigated pure liquids as well as solutions with surface active solutes. (C) 1998 Elsevier Science B.V. All rights reserved.