360-DEGREES AND 0-DEGREES WALLS IN MULTILAYER PERMALLOY-FILMS

360-degrees walls have been investigated in Permalloy double films and multilayers with intermediate layers of carbon, prepared by electron beam evaporation and dc triode sputtering. They are nucleated in an easy axis field when a Bloch line in one layer is trapped at an inclusion. To minimise the magnetostatic energy through the layers, the 360-degrees walls are inclined at an angle beta < 90-degrees, unlike the case for single films where beta = 90-degrees. They are very stable, requiring fields greater than 10H(k) to be saturated, although they can be erased or displaced by a moving domain wall. 360-degrees and 0-degrees walls, which appear when using a hard axis field, are also discussed.