Dislocation mobility for non-basal glide in ice measured by in situ X-ray topography

Abstract

Glide motion of edge dislocations in non-basal planes in ice has been observed under a compressive stress in the 〈1100〉 direction by X-ray topography using a high-power X-ray generator. From the observations, the dislocation velocities were determined quantitatively as a function of temperature in the range 223 to 263 K and stress in the range 0·1 to 1·4 MPa. The velocities obtained are proportional to an effective shear stress and are approximately five times larger than those for basal glide but with approximately the same activation energy of 0·6 eV.