Spin Structure in an Interfacially Coupled Epitaxial Ferromagnetic Oxide Heterostructure

We report the spin structure of an exchange-biased ferromagnetic oxide heterostructure, La0.67Sr0.33MnO₃/SrRuO₃, through magnetization and polarized neutron reflectometry measurements. We reveal that the magnetization reversal process of the La0.67Sr0.33MnO₃ biased layer critically depends on the frozen-in spin structure of the SrRuO₃ biasing layer during the cooling process. Furthermore, we observe unexpected double-shifted hysteresis loops of the biased layer that originates from the formation of lateral 180^∘{} magnetic domains within the biasing layer, a new mechanism not found in conventional exchange-bias systems.