Dislocations with ⟨100⟩ Burgers vectors in Ni3Al

The occurrence of dislocations with ⟨100⟩ Burgers vectors, the shortest unit translation in the Ll2 structure, is reported. The reasons which may explain why ⟨110⟩ Burgers vectors predominate during deformation are discussed on the basis of weak-beam observations. High Peierls forces on ⟨100⟩ dislocations, rather than anisotropy, are probably responsible for their rarity.