Formation of pentagonal atomic chains in BCC Fe nanowires

For the first time, we report the formation of pentagonal atomic chains during tensile deformation of ultra thin BCC Fe nanowires. Extensive molecular dynamics simulations have been performed on $<$100$>$/{110} BCC Fe nanowires with different cross section width varying from 0.404 to 3.634 nm at temperatures ranging from 10 to 900 K. The results indicate that above certain temperature, long and stable pentagonal atomic chains form in BCC Fe nanowires with cross section width less than 2.83 nm. The temperature, above which the pentagonal chains form, increases with increase in nanowire size. The pentagonal chains have been observed to be highly stable over large plastic strains and contribute to high ductility in Fe nanowires.