STM-mediated atom motion: a Co atom and mixed CoCun chains on a Cu(111) surface Renzhong Huang, Yusuning Sun, Cuicui Du, Tianfu Gao, Yuxi Wu and Valeris Stepanyuk Eur. Phys. J. B, 86 10 (2013) 429 Published online: 14 October 2013 DOI: 10.1140/epjb/e2013-40625-x