E. M. Nadgorny - Recent Papers

ABSTRACT

Motion of individual dislocations is usually described either by activation processes (low velocities, local obstacles) or viscous processes (high velocities, drag resistance). We developed a universal model that explicitly includes all those processes through non-uniform dislocation motion between randomly distributed local obstacles and the activated overcoming of the obstacles. Monte Carlo simulated activation events are affected by interaction of the moving dislocation with phonons and electrons. The model is in good agreement with available experimental data and, for the first time, able to explain qualitatively the effects of strong magnetic fields and the transition from normal to the superconducting state on the dynamical behavior of dislocations. The suggested model can be applied to a wide range of materials and phenomena when jerky dislocation motion is expected (such as the sharp yielding, dislocation sources, crack induced dislocation structures, etc.).