The asymmetry of the lobe contrasts in two‐beam TEM as a test to obtain the Burgers vector of an inclined relaxing dislocation

It is suggested that, if the elastic relaxation effect of an inclined dislocation at both free surfaces of a thin plate is taken into account, the determination of its Burgers vector b in two‐beam transmission electron microscopy can be obtained with a notable reduction of experimental work. The relaxation effect produces in general an asymmetric aspect of the lobe contrasts, with respect to a medium line perpendicular to the dislocation image segment. Indeed, from a re‐examination of about twenty micrographs of dislocations located in two different materials, it is concluded that a single experimental image is often sufficient to derive b . In no case three experimental images obtained with non‐coplanar diffracting vectors were found necessary to obtain unambiguously b .