A new technique for the quantitative investigation of magnetic structures in ferromagnetic
thin films is proposed. Unlike previous techniques the detected signal is simply related to the
magnetic induction in the film, and as such the direct determination of domain wall profiles is
possible. The technique utilizes a differential phase contrast mode of scanning transmission
electron microscopy in which the normal bright field detector is replaced by a split-detector
lying symmetrically about the optic axis of the system. The difference signal from the two …