The use of silver tips in scanning tunneling microscopy

Abstract

We propose to use silver tips for scanning tunneling microscopy (STM). Silver is the cheapest noble metal that is practically chemically inactive in the air environment. A simple reliable procedure of the tip preparation and resharpening is presented. The procedure is based on two-step electrochemical processing resulting in final tip curvature of less than 200 nm in radius as seen by an electron microscope. The tips show durability for at least a week of daily operation in an air STM.