A transmission electron microscopic investigation was made of planar defects in the -phase of a Ni alloy. This phase was considered to be a classic example of a topologically close-packed structure. For the first time, the fault vectors were determined exactly by using a combination of dark-field and high-resolution electron microscopy. The results were compared with the Marcinkowski-Miller model for -phase defects. A disagreement between the predicted and experimental results suggested that the modelling of defects in topologically close-packed phases had to be reconsidered.

A.Proult, P.Donnadieu: Philosophical Magazine A, 1995, 72[2], 403-14