Strain rate dependent mechanical properties in single crystal nickel nanowires

We measure the strain rate dependence of 0.2% offset yield stress in single-crystal nickel nanowires with diameters ranging from 80 to 300 nm. In situ tensile experiments with strain rates from 10(-4) s(-1) to 10(-2) s(-1) were conducted, and the small activation volume (similar to 10b(3), where b is the Burgers vector length) and high strain-rate sensitivity (similar to 0.1) were obtained. These results agreed with atomistic simulations. Our work provides insights into the strength-limiting and rate-controlling mechanism of plasticity at the nanoscale. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793481]