{001} faults in B2 Fe-40 at.% Al-0.7 at.% C-0.5 at.% B

The nature of planar defects in a quaternary Fe-40 at.% Al-0.5 at.% B0.7 at.% C alloy has been investigated using diffraction contrast analysis in a transmission electron microscope and via Z-contrast electron microscopy. From diffraction analysis, it is confirmed that the fringe contrast observed is due to complex planar faults on {100} planes with displacement vectors 1/2<100> lying in the fault plane. This conclusion is verified by direct observation of the faults using Z-contrast microscopy. In addition to the 1/2<100> in-plane shift, there is also an aluminium layer missing at the fault. These complex faults also display antiphase-boundary contrast when examined using a superlattice reflection.