The activation volume associated with the plastic deformation of ice

Stress relaxation experiments are carried out on single, bi, tri and quadri crystals of ice to obtain information on the rate controlling process. The results are analyzed with the rate theory developed previously. The study indicated that the energy barrier is asymmetrical and that the rate controlling process is associated with the Peierls barrier, with the dislocation intersection mechanism, or with the non-conservative motion of jogs. It seems unlikely that climb would control the dislocation motion in ice.Formerly Research Officer, Geotechnical Section, Division of Building Research, National Research Council of Canada, Ottawa.