Fig. 5

Pinning length (left, top), pinning stress (left, bottom) and pinning energy (right top and bottom) as functions of dislocation orientation angle, calculated for an equiatomic MgAl solid solution with parameters given in Table 1. Full circles indicate minima or saddle points determined from the full energy functional using a saddle point search, dashed lines correspond to maxima and minima computed from approximate semi-analytic solutions for the edge-like and screw-like limits. For the edge-like branch, one solves Eq. (8) with the functions given in Eqs. (14)-(16) and then inserts the result into (9)-(12). For the screw-like branch one proceeds in an analogous manner with Eqs. (19), (23) and (24). Both right figures contain the same information (energy vs angle) represented using different axis scaling, the bottom figure showing in more detail the angle dependency of energy minima and saddle point near the screw orientation