XPS and LEED study of Argon bombarded Al(1 1 1) surface

Argon ion bombardment on Al(1 1 1) leads to formation of adatoms and sub-surface bubbles. From X-ray photoemission spectroscopy study, we find that the Ar core-levels exhibit a systematic shift in binding energy and change in the line shape as function of ion incidence energy. This is related to the increase in size of the sub-surface bubbles created by argon ion bombardment where the Ar atoms are trapped. Low energy electron diffraction pattern for Al(1 1 1) exhibits broadened spots and enhanced background intensity after bombardment which is related to the formation of random steps and terraces on the surface