The recent development of scanning electron microscopy with polarization analysis (SEMPA) has made the direct measurement of magnetic structures with submicron spatial resolution possible. Because the secondary electron spin polarization is proportional to the magnetization in the area probed by the incident electron beam, the magnetization is measured directly, independent of topographic contrast. Topographic images are measured simultaneously, however, permitting comparisons between magnetic and structural properties. In addition the use of multiple, orthogonal detectors permits measurement of the magnetization magnitude and direction. We have recently used this technique to look at various Fe-rich amorphous ferromagnetic alloys. In particular SEMPA was used to examine the rotation of the magnetization within domain walls and to study changes in magnetic microstructure due to Ar ion bombardment and annealing.
Citation: Journal of Applied Physics
Pub Type: Journals