SEMPA domain observation compared to three other methods

SEMPA (scanning electron microscopy with polarization analysis) is compared to well-known methods of magnetic imaging, Bitter colloid, longitudinal magnetooptical Kerr effect (MOKE), and Lorentz transmission electron microscopy (LTEM), with no extraordinary image processing. Resolution is established by direct micrograph measurement of the smallest structure available. The images have been acquired using a thin-film (35-nm) Permalloy chevron-shaped object. Bitter images gave their usual delineation of domain walls. Longitudinal MOKE images produce results similar to Bitter images; however, diffraction patterns near the chevron's boundary blurred the magnetic information. The LTEM micrographs provided by far the most qualitative data about the magnetization of the chevron; magnetization ripple structure was apparent. SEMPA images are produced with the highest magnification, 5000×, and the present generation of instrumentation did provide quantitative information about surface magnetization. However, the angle of magnetization in the plane of the film suffers from instrumental and electronic asymmetries. The magnitude of magnetization information appears to be consistent, even though it is uncalibrated