Velocity of twinning partial dislocations in silicon

Abstract

The growth velocities of deformation twins in the tangential direction are measured in silicon single crystals by the four-point bending method for temperatures between 350 and 500 °C and for shear stresses τ between 80 and 550 MPa. Stress and temperature dependences of the twin growth are found to satisfy the same empirical power-law equation as that for the motion of slip dislocations. Comparing the velocity of twin growth with that of slip dislocations, it is found that the activation energy is not much different between them, but the stress dependence of the twin growth is larger than that of the slip dislocation. The latter fact relates to the twinning dominantly observed under the high-stress condition (τ>260 MPa). Referring to the subsequent paper [J. Appl. Phys. 61, ▪▪▪ (1987)], the velocity data in this report are representative of the velocity of individual twinning partial dislocations which move on the coherent twin boundary.