Abstract
Metal impurities, gold, chromium and titanium, have been deliberately introduced into graphene. The structural and topographic properties of doped graphene have then been studied by using conventional transmission electron and aberration corrected scanning transmission electron microscopy. Analysis revealed that metal atoms cluster preferentially in/on contaminated areas. Contrarily to observations that gold atoms do not adhere to clean patches of monolayer graphene, chromium and titanium were found to be more reactive with clean monolayer graphene, and the coverage was higher than for gold for the same evaporated amount.