Microscopic deformation mechanisms in InP single crystals

Undoped and Zn-doped InP single crystals were deformed in compression in single-slip orientation. Different strain rates and temperatures were applied to deform the samples up to stage III, the first recovery stage. Transmission electron microscopy was used to characterize the evolution of the dislocation structure in the different stages of the deformation, the easy-glide region (stage I), the first work-hardening stage (stage II) and the first recovery stage (stage III). Stage I of the plastic deformation is characterized by dislocations of the primary slip system. Predominantly edge dislocations and edge dipoles are observed, resulting most probably from the cross-slip of screw dislocations. The dislocation structure of deformation stage II consists mainly of rectangular dislocation networks extended parallel to the primary glide plane. The dislocation density is further increased in stage III. A cell structure is observed, which consists of dense dislocation networks surrounding regions nearly free of dislocations. The detailed contrast analysis of the different dislocation types indicates that the recovery is governed by climb processes.