Magnetic force microscopy study of a defect-induced orthogonal magnetic structure on a cobalt film

An unusual orthogonal magnetic structure is observed on a cobalt film by ma gnetic force microscopy. The structure is composed of a double wall, which is caused by a surface scratch, and two perpendicular spike domains, which are caused by an internal defect. The occurrence of the structure is attrib uted to the generation of surface free poles due to film inhomogeneities an d their redistribution to reduce the magnetostatic energy. The magnetizatio n pattern has also been proposed to explain the observed magnetic force ima ge. (C) 2000 Elsevier Science B.V. All rights reserved.