Propagation Of Exchange Bias In Cofe/femn/cofe Trilayers

摘要

CoFe/FeMn, FeMn/CoFe bilayers and CoFe/FeMn/CoFe trilayers were grown in magnetic field and at room temperature. The exchange bias field H_(EB) depends strongly on the order of depositions and is much higher at CoFe/FeMn than at FeMn/CoFe interfaces. By combining the two bilayer structures into symmetric CoFe/FeMn(t_(FeMn))/CoFe trilayers, H_(EB)~t and H_(EB)~b of the top and bottom CoFe layers, respectively, are both enhanced. Reducing t_(FeMn) of the trilayers also results in enhancements of both H_(EB)~b and H_(EB)~t. These results evidence the propagation of exchange bias between the two CoFe/FeMn and FeMn/CoFe interfaces mediated by the FeMn antiferromagnetic order.