It was noted that barriers of very different characteristics, such as localized obstacles and the extended Peierls-Nabarro relief, could control dislocation motion in crystals over various stress and temperature ranges. The large differences in the microscopic parameters (such as activation volumes) which characterized these 2 mechanisms were seen, even at the macroscopic scale, as a marked change in the plastic properties over a rather narrow transition range of temperatures. A theory was developed which described the temperature dependence of the flow stress and the strain-rate sensitivity near to the transition. Its predictions were compared with experimental data on the plastic deformation of cubic zirconia single crystals having a soft orientation.

Temperature Dependence of the Flow Stress and the Strain Rate Sensitivity at the Transition from the Peierls Mechanism to Pinning by Localized Obstacles. B.V.Petukhov, M.Bartsch, U.Messerschmidt: European Physics Journal, 2000, 9[2], 89-95