Ion-induced desorption in the near-threshold regime

Abstract

Under the condition that adsorbate atoms are isolated from each other, an analytic formula for the threshold energy of ion-induced desorption is derived for possible combinations of projectile, adsorbate atom, and substrate atom. The threshold energy of the ion-induced desorption corresponds to the collision sequence near the surface which gives the minimum energy loss. The obtained formula includes explicitly the angle of incidence, and the ion-induced desorption threshold is found to depend strongly on the combination of the projectile, the substrate atom and the adsorbate atom. The minimum energy loss process which corresponds to the threshold mechanism says that the particle with the smallest mass among the projectile, the substrate atom and the adsorbate atom should move in the substrate.