Dislocation reactions in ZrN Original Research Article

Transmission electron microscopy analysis of an annealed and quenched foil of ZrN revealed that 1/2110 single dislocations dissociate into two 1/6112 Shockley partial dislocations bounding an intrinsic stacking-fault (SF). The 1/2110 single dislocations have a super-jog character and are not coplanar with the dissociated Shockley partials. All dislocations and SFs were found to lie on {111} planes, indicating that a possible slip system is {111}〈110〉. The dislocation reactions are the same as those observed in usual face-centered cubic metal alloys, although ZrN has an ordered NaCl-prototype structure. The stacking-fault energy (SFE) of ZrN was calculated based on the separation of the Shockley partial dislocations and had an unusually low value of approximately 4.1 mJ/m2. Both the dislocation dissociation reaction and anomalously low SFE can be explained by the large vacancy concentration in ZrN, which was confirmed by the appearance of diffuse intensity maxima in electron diffraction patterns due to short-range ordering of N vacancies.