Role of a single surface vacancy on the tensile stress-strain relations of single crystal Ni nanowire

Using molecular dynamics (MD) simulation method, we have studied the stress-strain response of the single-crystalline Nickel nanowire containing a single surface defect. To gain quantitative understanding on the deformation process, we have systematically studied the effect of nanowire cross-section, nanowire length, temperature, randomness in defect location and location of defect from nanowire edge on the tensile mechanical properties of defective Ni nanowires and contrasted with the perfect systems. In each case study, we investigated the comparative deformation processes and the associated stress-strain laws to reveal the role of single defect on the mechanical behavior of Ni nanowires. Our study reveals that even a single defect can cause significant degradation in the failure strength and toughness of nanowires as long as the cross section of nanowires are in the nanometer range. Our study also reveals that the effect of point defect becomes less critical when nanowires become thicker.