Polarity in bending deformation in InSb crystals

Abstract

A geometrical consideration of the configuration of {111} tetrahedra in a bent crystal having the sphalerite structure shows that the type of bending is reversed between the primary slip plane and some of the secondary slip planes. This explains why the secondary slip is activated and the primary slip plane becomes forest-rich in β-bending. Two types of experiments establish the origin of the higher flow stress in β-bending compared with α-bending. It is concluded that the difference in the flow stress between the two types of bending in the deformation stage after the lower yield point originates mainly from the difference in the activity of the secondary slip system, while that in the early stage of deformation originates from the difference in the rate of increase in the density of screw dislocations due to the difference in the mobility between α-dislocations and β-dislocations moving on the primary slip plane.