Kinetic model for the long term stability of contaminated monoatomic nanowires

The kinetic behavior of pure Au nanowires upon rupture is analyzed in comparison with that of nanowires contaminated with H and C. The latter present larger activation energies for the rupture for all elongations and as a consequence these contaminated wires are predicted to live longer, as observed experimentally. The kinetic analysis is complemented by an analysis in terms of the concept of reaction force. It is found that this is the relevant quantity to analyze when considering the stability of the nanowires in the limit of low elongations rates or relatively high temperatures rather than the longitudinal force acting on the nanowire. The elastic and electronic contributions to the rupture process are obtained for each system. While the latter are similar in all cases, the elastic part is found to play the decisive role to make the difference. The present results suggest that measurement of the force constant of the junction may help to determine the chemical nature of the impurity.