The positive temperature dependence of the yield stress of this intermetallic compound was considered. Proposed models, based upon cross-slip events from primary octahedral to cube slip planes, explained the phenomenon in terms of dislocation velocity or mobile dislocation density effects. In situ atomic force microscopic observations of Ni3(Al,Hf) single crystals under increasing strain were reported. The fine slip line structure provided a direct evidence of a permanent locking of mobile dislocations in the yield stress anomaly domain.

How do Nanometer Scale Dislocation Traces Evolve in the Stress Anomaly Domain of Intermetallics? Coupeau, C., Bonneville, J.: Applied Physics Letters, 2007, 90[17], 171914