The fabrication of MgB2 superconducting STM tips

We demonstrate a simple method for the fabrication of reproducible, clean and stable MgB2 superconducting tips. The quality of these tips has been verified by imaging the surface of a thin Au(111) film sample using a low temperature scanning tunneling microscopy (STM). High-quality semi-atomically resolved STM surface images of the Au(111) sample have been observed using the MgB2 superconducting tip, which unambiguously indicates that the fabrication of relatively superconducting MgB2, suitable for use as STM tips, is feasible. (C) 2003 Elsevier Science B.V. All rights reserved.