Spring magnet behavior in DyFe2/YFe2 Laves phases superlattices

Original composite systems with two isomorphous Laves phases (DyFe2 and YFe 2) have been elaborated by molecular-beam epitaxy. These superlattices comb ine the hard magnetic properties of DyFe2 with the soft ones of YFe2. Moreo ver, they exhibit high single-crystal quality and constitute model systems to investigate the influence of the relative energy terms on the magnetizat ion reversal. The magnetization measurements show that it is thus possible to tailor the magnetic configuration and the magnetization reversal process . Particularly interesting behaviors have been observed in the superlattice [DyFe2(50 Angstrom)/YFe2(130 Angstrom)], which presents spring ferrimagnet characteristics, together with an exchange bias of the hysteresis loop. Th e bias can he either positive or negative, depending on the cooling-field v alue and, therefore, shows memory of die magnetic history of the superlatti ce. The spring-magnet loop appears to be reversible over the (-7.5 T/+7.5 T ) field range at low temperature.