The role of entropy in thermally activated deformation: Application to the study of irradiation hardening in LiF

Abstract

Abstract An experimental study of low temperature deformation of irradiated lithium fluoride is presented. Results are discussed in terms of the rate process theory, and it is shown that only the entropy contribution arising from the temperature dependence of the shear modulus is needed to give a self-consistent analysis of the experimental data. On that basis a new procedure to determine the Gibbs free energy from the stress dependence of activation volume is outlined.