DISCOVERY OF CROSS-TIE WALLS AT SAW-TOOTH MAGNETIC DOMAIN BOUNDARIES IN PERMALLOY-FILMS

Scanning electron microscopy with polarization analysis was used to im age the surface magnetic domain structure of permalloy films (350 Angs trom 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 sta te of the films, saw-tooth domain boundaries separating two large appr oximately head-on domains were observed. At high magnification, cross- tie walls were seen with a periodic vortex structure along the straigh t edges of the saw-tooth domain boundaries. (C) 1998 American Institut e of Physics.