Type II magnetic contrast was first observed by Philibert and Tixier and relies on the change in the effective backscattering coefficient due to interaction of the scattered electrons within the specimen and the local magnetic induction (for a review see Tsuno). Depending on the tilt of the specimen and the position of the backscattered electron detector(s), contrast due to the presence of either or both domains and domain walls can be obtained; in the case of the latter, the standard geometry is for the specimen to be normal to the incident beam and the detectors are positioned above it and close to the optic axis. This is the geometry adopted in our studies, which used a JEOL 2000FX with a special split objective lens polepiece; this permitted the specimen to be in magnetic field-free space, the separate lens gaps above and below allowing good probe forming capabilities combined with excellent Lorentz imaging performance. A schematic diagram is shown in Fig. 1.
SEM Applied on Magnetic Materials: Magnetic Contrast and Morphology Imaging
