Electrochemically etched nickel tips for spin polarized scanning tunneling microscopy

Abstract

A fast and simple method for the electrochemical preparation of sharp Ni tips for spin polarized scanning tunneling microscopy (STM) is reported. These Ni tips perform well also in conventional STM experiments, being able to achieve reproducible atomic resolution on graphite. Ni tips combine the advantages of both Pt/Ir tips, since they are oxide free, and of W tips because of the greater reproducibility and control of the tip apex by means of the etching protocol, as compared to freshly cut tips.