Fig. 3
The nanowire growth for different pulling direction. a–c When pulling the tip towards the top right, the surface of the nanowire assumes a saw-tooth shape. A white cross with vertical line parallel to the \([02\bar 2]\) direction of the nanowire marks the track of the movement of the pulling tip. The contour of two aluminum teeth is delineated with dashed black line and superimposed onto (c) for comparison. d, e When the pulling direction is upward, the nanowire morphology is relatively smooth. Inset in (d) shows a grain boundary (GB) in the neck region. f Dark-field image of the formed nanowire indicates single-crystalline internal structure. Inset is the diffraction pattern of the nanowire. Scale bars, 500 nm
