SIMULATIONS OF SPIN DYNAMICS IN COBALT-BASED MAGNETIC MULTILAYERS

A model of a magnetic multilayer structure in the micromagnetic approx imation is outlined and applied to the study of cobalt-based multilaye rs with nonmagnetic spacers. The field swept ferromagnetic resonance i s studied in athermal simulations with continuous cobalt layers and wi th granular cobalt layers with nonmagnetic grain boundaries. Results a re obtained which agree qualitatively with recent experimental observa tions. The response of the systems are analyzed in terms of the elemen tary excitations by introducing a Hamiltonian formalism and spectral d ecomposition. The eigenfrequencies of the, continuous magnetic medium are found to differ dramatically as compared to the granular magnetic medium confirming the break up of the intralayer symmetry produced by the nonmagnetic grain boundaries. [S0163-1829(98)03741-2].