Figure 2

Mechanical response and deformation morphology of nano-moulded MG nanowires.

(a), Representative stress strain curves obtained from in situ tensile testing of as-moulded, focused Ga⁺ ion irradiated and irradiated and annealed (T = 0.96T_g) nanowires with diameters ranging from ~100–150 nm. Ion irradiation induces changes to the material allowing for tensile ductility, in contrast to the brittle response measured in all as-moulded nanowires. Upon annealing irradiated nanowires below T_g, subsequent tensile testing shows a return to the brittle state, suggesting the mechanical response may be tunable. The measured mechanical response is supported by different morphology for the different preparation conditions, shown in SEM images for: (b), as-moulded, (c), ion-irradiated and (e), irradiated and annealed fractured nanowires. (d), TEM image of deformed ion-irradiated nanowire, showing clear evidence of plastic flow in the irradiated region. (e), TEM image of the fracture site in a MG nanowire subjected to focused Ga⁺ ion irradiation at a dose of 305 ions/nm² showing ductile morphology following tensile testing. (g), high resolution TEM image showing heavily deformed ductile zone of fracture surface. No evidence of crystallization is observed, as confirmed by the FFT of the image (inset), suggesting that ductility is accommodated entirely by structural changes to the glass.