Abstract
An unusual orthogonal magnetic structure is observed on a cobalt film by magnetic 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 attributed to the generation of surface free poles due to film inhomogeneities and their redistribution to reduce the magnetostatic energy. The magnetization pattern has also been proposed to explain the observed magnetic force image.