WALL STRUCTURES IN FERRO ANTIFERROMAGNETIC EXCHANGE-COUPLED BILAYERS - A NUMERICAL MICROMAGNETIC APPROACH

Two-dimensional wall structures in ferro/antiferromagnetically exchange-coupled bilayers are calculated by means of numerical micromagnetic simulations. Extended wall tails occurring in non-compensated structures are duly accounted for via the introduction of a variable meshing along one space direction. Constant charge finite volumes and the application of general boundary conditions in the presence of interlayer exchange coupling and/or surface anisotropy further characterize the computation scheme. Simulated wall structures in zero field are compared with various approximate analytical models and the ranges of validity of the latter are made explicit. Hard-axis field intrinsic magnetization and hysteresis properties are outlined, and a sketch of the wall structure phase diagram is proposed for given material parameters and a specific geometry.