Quantum Effects in the Plasticity of Crystals

Abstract

Abstract Below about a quarter of the Debye temperature the rate processes controlling creep and plastic yielding in crystalline materials are found to be increasingly less temperature dependent as T → 0. These observations, and the occurrence of creep down to helium temperatures, are not encompassed by classical rate‐theory. The effects are shown to be explicable in terms of the contribution of the zero‐point energy to the vibrational spectrum of the lattice: below a certain temperature this necessitates replacing kT in the classical Arrhenius rate‐equation τ −1 = v exp (− u/kT ) by k ( T 0 + AT 2 ), where T 0 and A are constants.