Dislocations and plastic deformation of ice

Abstract

Dislocation structures of dendritic crystals of ice have been studied by-x-ray diffraction topography. Only 〈1120〉 type Burgers vectors were observed with slip on {0001} planes and pyramidal cross slip planes. Prismatic punching, reactions of the basal dislocations, pile-ups and many of the general characteristics of dislocations in more refractory tetrahedrally coordinated hexagonal crystals were found. There was no evidence for widely separated partial dislocations or for Burgers vectors not lying in the basal plane. These results suggest that more complex processes than simple slip are involved in the plastic deformation of potycrystalline ice.