Electrochemical etching of sharp tips for STM reveals singularity
Mikroelektronik Centret (MIC), Technical University of Denmark
DK-2800 Lyngby, Denmark
2 The Niels Bohr Institute, University of Copenhagen Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark
Accepted: 28 November 2001
Electrochemical etching of metal wires is widely used to produce atomically sharp tips for use in scanning tunneling microscopy (STM). In this letter we uncover the existence of a finite-time singularity in the process: Several of the physical parameters describing the system exhibit scaling towards and away from a particular singular point in time, exactly the time at which the wire breaks. The obtained scaling exponents coincide with exponents reported from other singular dynamical systems. The results also provide knowledge of how to control STM tip properties on the nano-scale.
PACS: 89.75.Da – Systems obeying scaling laws / 07.79.Cz – Scanning tunneling microscopes / 82.45.Qr – Electrodeposition and electrodissolution
© EDP Sciences, 2002