Electrochemical fabrication of cobalt and nickel tips for scanning tunneling microscopy

Scanning tunneling microscopy (STM) is a powerful technique to map the distribution or the density of electronics states of conductive surfaces with angstrom (A) resolution. STM requires sharp conductive tips in order to operate in ambient conditions. which ore stable with respect to oxidation, We describe a procedure to obtain high quality tips from wires of different materials such as Co and Ni. We discuss in detail the electrochemical process employed in the fabrication of the tips and assess the shape of the tips by optical microscopy and scanning electron microscopy (SEM), These tips yield high-resolution STM images even after a few weeks of exposure to air.