The micromagnetic ground states in epitaxial Fe (0Â 0Â 1) microstructures

The magnetic structure of planar epitaxial microstructures Fe (0 0 1) fabricated as rectangles and crosses of 200 nm to 20 μm sizes was studied using magnetic force microscopy and micromagnetic calculations. Most characteristic micromagnetic ground states were examined. The effect of microstructure sizes and orientation, with respect to the crystallographic axes, on the magnetic structure was considered. It was found that the micromagnetic ground state is a sequence of vortices or a diamond structure and also the Landau structure when the long microstructure axis is parallel to the easy axis of magnetization (EAM). When the microstructure sizes become smaller than 0.5 μm, micromagnetic states convert to a quasisingle-domain state. In microstructures oriented along the hard axis of magnetization in the film plane, micromagnetic ground states display either a concertina structure or a sequence of vortices and antivortices. In cross-shaped microstructures, the magnetic structure of the arms of the cross was found to be similar to that observed in rectangular microstructures of the same size and orientation relative to the crystallographic axes. However, the magnetic structure of the central part of the cross is not a superposition of the magnetic structures extended from the arms. It is determined by the EAM direction.