Element-selective single atom imaging

Electron energy-loss spectroscopy (EELS) is widely used to identify element al compositions of materials studied by microscopy. We demonstrate that the sensitivity and spatial resolution of EELS can be extended to the single-a tom Limit. A chemical map for gadolinium (Cd) clearly reveals the distribut ion of Cd atoms inside a single chain of metallofullerene molecules (Gd@C-8 2) generated within a single-wall carbon nanotube, This characterization te chnique thus provides the "eyes" to see and identify individual atoms in na nostructures. It is likely to find broad application in nanoscale science a nd technology research.