ENERGIES OF UNUSUAL MAGNETIC DOMAIN WALLS IN VERY THIN FILMS

The energies of domain walls in which the magnetization vector on either side of the wall is oriented perpendicular to the plane of the wall have been estimated. Three distinct types have been considered, namely the 180°wall, 360°wall and a multiple wall system comprising a series of 180°walls. The 360°wall has a non-zero wall width only as the result of an exchange term, whereas the other two walls have finite widths even in the absence of exchange. It is found that these 'unusual' boundaries have energies very much higher than normal Néel walls except at very low thicknesses. However, it is predicted that 360°walls could occur in very thin films as observed experimentally.