JUMP-LIKE TWIN BOUNDARY MOVEMENT IN INDIUM CRYSTALS

This is an investigation of the specific features of twin boundary movement by creep in indium crystals at room temperature. It has been shown that in the most structurally perfect crystals, broadening of twin layers is jump‐like. Jumps in the kinetic relations for boundary displacement are the most pronounced in the stress range where the initial boundary velocity becomes as high as (5 × 10−5–10−4) cm/s. The effect of the applied stress on the average jump density and the characteristic boundary motion velocities, that is the initial velocity, the velocities at the jump and just before it were investigated. Dislocation structure deterioration as well as impurity increase lead to changes in the boundary motion character, namely to monotonic reduction of boundary velocities with time. It has been ascertained that the jump‐like nature of the boundary motion is due to boundary interaction with obstacles present in the crystal and unambiguously associated with periodically changing boundary structure: defect formation and eventual defect inclusion into the twinned material. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim