A Monte Carlo study of the magnetization reversal in DyFe2/YFe2 exchange-coupled superlattices

Monte Carlo simulations are used to perform an atomic scale modeling of the magnetic properties of epitaxial exchange-coupled DyFe2/YFe2 superlattices. These samples, extremely well-researched experimentally, are constituted by a hard ferrimagnet DyFe2 and a soft ferrimagnet YFe2 antiferromagnetically coupled. Depending on the layers' thickness and on the temperature, the field dependence of the magnetization depth profile is complex going from a unique giant ferromagnetic block to exchange spring behavior when the soft YFe2 layers reverse for positive bias fields. In some particular conditions of temperature and layers׳ thicknesses, it can even be easier to reverse the hard thin DyFe2 layers for positive fields, while the soft thick YFe2 layers keep their magnetization along the field. In this work, we reproduce by Monte Carlo simulations hysteresis loops for the net and compound-specific magnetizations at different temperatures, and assess the quality of the results by a direct comparison to experimental hysteresis loops.