Nanometer-scale electrochemical deposition of silver on graphite using a scanning tunneling microscope

Abstract
Silver pillars, 10–30 nm in diameter and 4–10 nm in height, were generated on graphite surfaces using a scanning tunneling microscope. These structures were produced following the application of tip(+), 6 V×50 μs bias pulses in dilute, aqueous silver fluoride. A pit on the graphite surface is formed during the first 5μs of the pulse, followed by nucleation and electrochemical deposition of silver at this pit. This two-step mechanism allows silver pillars to be located with a high lateral precision on the graphite surface−independent of the proximity of the tip to preexisting nucleation sites such as step edges.