Unconventional switching behavior in La0.7Sr0.3MnO3/La0.7Sr0.3CoO3 exchange-spring bilayers

We report on the observation of exchange-spring behavior in complex oxide bilayers composed of high coercivity ferromagnetic (FM) La0.7Sr0.3CoO3 (LSCO) and low coercivity FM La0.7Sr0.3MnO3 (LSMO). The magnetization process from each individual layer is revealed by a combination of bulk magnetometry and x-ray magnetic circular dichroism measurements. The results show unexpected magnetic switching behavior which deviates from conventional exchange-spring systems in that reversible switching occurs not only within the soft LSMO layer but is also accompanied by the switching of an interfacial LSCO layer. The origin of such exchange coupling is discussed in terms of charge redistribution at the interface