Electroplastic effect in Ca²+-doped KCl single crystals

Abstract

The application of electric fields up to 6 MV m-1 reduces the flow stress during constant-strain-rate deformation of KCl containing 90 mol.p.p.m. Ca²+. These stress drops have been measured for various magnitudes and directions of electric field. It was found that the amount of stress drop is dependent on the component of electric field along the direction of Burgers vector. These effects are quantitatively interpreted by the charged-dislocation model which was first proposed by Whitworth in 1976 and which is modified in this paper. The charge values estimated in this model are 2.8 × 10⁻¹⁰Cm⁻¹ for a rapidly cooled crystal and 1.9 × 10⁻¹⁰CM⁻¹ for a slowly cooled crystal.