STM studies of the N/Cu(111) system: surface structure, electron confinement and tip-induced modification A. M. Goedken, S. L. Silva, S. M. York and F. M. Leibsle Eur. Phys. J. AP, 19 2 (2002) 77-82 Published online: 24 July 2002 DOI: 10.1051/epjap:2002051