Discovery of cross-tie walls at saw-tooth magnetic domain boundaries in permalloy films

Scanning electron microscopy with polarization analysis was used to image the surface magnetic domain structure of permalloy films (350 Angstrom Ni83Fe17) in ultrahigh vacuum. These thin-him materials are used in a variety of magnetoresistive sensing applications, which depend on the state of the domains present in the film. In the demagnetized state of the films, saw-tooth domain boundaries separating two large approximately head-on domains were observed. At high magnification, cross-tie walls were seen with a periodic vortex structure along the straight edges of the saw-tooth domain boundaries. (C) 1998 American Institute of Physics.