Nanowires and Suspended Atom Chains from Metal alloys
  We present a study of the elongation and rupture of gold-silver alloy nanowires. Atomistic details of the evolution were derived from time-resolved atomic resolution transmission electron microscopy and molecular dynamics simulations. The results show the occurrence of gold enrichment at the nanojunction region, leading to a gold-like structural behavior even for alloys with minor gold content. Our observations have also revealed the formation of mixed (Au and Ag) linear atomic chains. 
J. Bettini, F. Sato, P.Z. Coura, S.O. Dantas, D.S. Galvao and D.   Ugarte