Uniaxial tensile behavior of a bicrystal copper nanowire: Structural characterization with a Fourier transformation method

Molecular dynamics simulations have been used to investigate the uniaxial tensile behavior of the [1 1 0]‖[1 0 0] bicrystal copper nanowire. Due to the effect of grain boundary, the bicrystal nanowire breaks at the interface with strain increasing, showing a unique brittle feature. In order to well understand the crystallographic characters, we have developed a discrete Fourier transformation technique to analyze the periodic crystal structure. In particular, the atomic density distribution along the long axis of the nanowire is transformed into a frequency–amplitude relationship or into a normalized atomic density distribution. These two treatments enable us to further study the crystal grain orientation and the crystal structure in the stretching process. The frequency–amplitude analysis provides information about the large-scale crystallographic features while the local characteristics are mainly determined by the normalized atomic density distribution. From analyses of the simulation data, we have found that [1 1 0]‖[1 0 0] keeps good crystalline structure until breaking.