ON THE DEFECT STRUCTURE DUE TO LOW-ENERGY ION-BOMBARDMENT OF GRAPHITE

Graphite surfaces cleaved perpendicular to the c axis have been irradi ated with low doses of Ar+ ions at 50 eV kinetic energy and perpendicu lar incidence. Scanning tunneling micrographs (STM) of these irradiate d surfaces exhibited dome-like features as well as point defects. Thes e dome-like features retain undisturbed graphite periodicity. This fin ding is attributed to the stopping of ions between the first and secon d graphite sheets. The possibility of doping semiconductors at extreme ly shallow depths is raised.