Action of electric fields on the plastic deformation of pure and doped ice single crystals

Abstract

A strong effect was found of a relatively small (about 50 V) d.c. voltage applied across thin (10–200 μm) single crystals of ice Ih on their plastic deformation. In pure and doped (HF and KOH) crystals, the application of a d.c. voltage causes a reversible drop in the creep strain rate at temperatures from −10 to −45°C. The application of an a.c. electric field of the same strength (as the d.c. field) to thin specimens or the application of a d.c. electric field to thick specimens (1–3 mm) did not reveal changes in the plastic strain rate. It was also found that d.c. voltage causes a significant decrease in the high-frequency conductivity of ice controlled by majority-charge-carrier concentration (L and D defects). Experiments on the injection of minority charge carriers in ice did not show noticeable changes in the plastic flow rate. The significance of these results for different physical models of dislocation motion is discussed.