It was recalled that the Haasen phenomenological description of the thermally activated dislocation velocity, in materials with high Peierls barriers, involved constant parameters such as the stress exponent and the normalizing stress. These could be determined experimentally, but had no direct physical meaning. By assuming that this phenomenological description was equivalent to the classical thermodynamic one, and by using results which linked the activation volume and the effective stress to the relaxation volume and the applied stress, explicit expressions were obtained for these quantities in terms of the classical ones of the thermodynamic approach.

I.Zongo, J.L.Farvaque: Physica Status Solidi A, 1994, 142[2], 383-8