Argon Nanobubbles in Al(111): A Photoemission Study

Two fundamental manifestations of Al conduction electron response to Ar atom core hole in the final state of photoemission have been studied in implanted Ar bubbles in Al(111). Ar 2p binding energy and the Doniach-Sunjić asymmetry of the core-level line shape vary systematically as functions of Ar+ implantation energy and number of ions bombarded (fluence). The observations are explained by relating the strength of Al conduction electron screening to the size of the Ar nanobubbles.