Atomic emission from a gold scanning-tunneling-microscope tip

We have demonstrated that a gold scanning-tunneling-microscope tip can be used as a miniature solid-state emission source for directly depositing nanometer-size gold structures. The emission mechanism is believed to be field evaporation of tip atoms, which is enhanced by the close proximity of the substrate. The technique has been used in air on Ag(111) surfaces to write several thousand features with no apparent degradation of the tip's ability to emit atoms.