Fig. 4.

Recurrence of the B2 superstructure in a HPT-deformed sample heated up to 170 °C. (a) Dark-field image taken with a fundamental reflection (g = [200]). The contrast variations show the substructure of the grain (dislocations and small angle grain boundaries). (b) Dark-field image of the same area as (a) taken with a superlattice reflection (g = [100]). Small ordered domains (<5 nm) inside the grain are revealed. (c) Diffraction pattern illustrating the positions of the objective apertures that were used for (a) and (b).