Dislocation Motion in Secondary Slip Planes in Alkali Halide Crystals at Room Temperature

Dislocation motion in {100} 〈110〉 and {111} 〈110〉 secondary slip systems has been observed in NaCl, KCl, KBr, KI, and RbI crystals at room temperature by means of a special loading and etch‐pit technique. The observed reduction in the difference between the critical resolved shear stress τ s{110} in the primary slip system {110} 〈110〉 and τ s in the secondary slip system in the above sequence of crystals demonstrates the increasing influence of multiplication processes of dislocations on dislocation motion in the primary system. A considerably lower effect of γ‐irradiation on τ s{100} and τ s{111} has been found in comparison with that of τ s{110} . Possible reasons are discussed briefly.