A thermally activated model for room temperature creep in nanocrystalline Au films at intermediate stresses

Uniaxial tension creep experiments conducted on free-standing nanocrystalline Au films with 40 nm grain size showed high initial primary creep rates of 3.3 × 10−8–2.7 × 10−7 s−1, reaching steady-state creep rates of 5.5 × 10−9–1.1 × 10−8 s−1 after 5–6 h. The isochronous creep curves pointed to the need for a nonlinear creep model based on the kinetics of thermal activation, which captured well the effect of applied stress amplitude. The implications of this model on the long term stability of nanocrystalline films were explored numerically for periodic stress profiles.