Plastic deformation, extended stacking faults and deformation twinning in single crystalline indium phosphide 2. S doped InP

Sulphur doped InP single crystals were deformed by compression in dual and multislip conditions at a low shear strain rate (∼2 × 10−5 s−1) and moderate temperature (∼ 0.4T m). Hardening curves show a very different behaviour from pure InP, although the S does not have a net hardening effect at the yield point for the investigated testing conditions, contrarily to what is observed at higher temperatures. Transmission electron microscope observations of deformed samples have revealed extended stacking faults similar to those observed in pure InP, but also numerous twins or microtwins which were not observed in the latter case. Partial dislocation configurations suggest that pole mechanisms are operative. No evidence could be found that extrinsic stacking faults act as twin nuclei. The role of S in twinning is discussed.