The structure of [010] dislocations in Ni3Al

In Ni{sub 3}Al at temperatures above the peak in flow stress activity of dislocations in {l_brace}100{r_brace} cube planes is observed which is carried by dislocations of type a/2 [011]. In principle cube glide could also occur by dislocations of type a [010] and they might have a lower line energy than the type a/2 [011]. Such dislocations of type a [010] have been observed as short segments in TEM observations in Ni{sub 3}Al but they seem neither to multiply nor to propagate. Therefore they must have either a high Peierls stress or they must form locked configurations. In this paper the authors calculate the {l_brace}100{r_brace} {gamma}-surface of Ni{sub 3}Al by the ab-initio electron theory and redo the calculations within the general Peierls model with this more realistic {gamma}-surface.