Effect of a high hydrostatic pressure on the dynamic instability of dislocation motion

The effect of a high hydrostatic pressure on the dislocation dipole vibration frequency and the forces of dynamic drag of dislocations by dislocation dipoles and of dislocation pairs by pinned dislocations is studied. Analytical expressions are obtained for the force of dynamic drag of mobile dislocation pairs by pinned dislocations and for the force of drag of isolated dislocations by dislocation dipoles in hydrostatically compressed crystals. Hydrostatic compression leads to a significant increase in these forces. This effect is most pronounced in alkali-halide crystals, where the drag force increases by a factor of 1.5–2.0.