Effect of mean-square amplitude of atomic vibrations on the creep behaviour of cubic crystals

Correlation between the activation energy Q of high-temperature creep and t he Debye-Waller thermal parameter B, which is proportional to the mean-squa re amplitude of atomic vibrations, has been examined in the case of 17 face d-centred cubic, body-centred cubic and diamond-structure cubic elements. I t is observed that Q is a function of B, irrespective of the crystal struct ure; Q decreases as B increases. The correlation is governed by the power-l aw Q = Q(o)(B/B-o)(Mo), where Q(o) = 0.095 eV and M-o = -0.62 are numerical constants determined by least-squares fit method, and the constant B-o = 1 nm(2).