Fim study of F.C.C. iron particles in Cu

Fe particles in a Cu-1.5% Fe alloy were examined by a field ion microscope (FIM). The atomic arrangement of f.c.c. iron particles was clearly resolved. The observed f.c.c. particles which were partially exposed from the Cu matrix were coherent with it and stable even at ~20K and under the high stress induced by an applied electric field. No dislocations were found at the interface of the particle and the Cu matrix and the stability of the particle was attributed to this absence of dislocations. An atom-probe analysis showed that Fe particles, larger than 5 nm, consisted of almost 100% of Fe atoms and had a sharp interface with the Cu matrix with respect to composition.