Magnetic configurations in exchange-biased double superlattices

The layer-by-layer magnetization of a "double-superlattice" Fe/Cr(211) exch ange-bias junction was determined by polarized neutron reflectometry. An n- layered [Fe/Cr](n) antiferromagnetic (AF) superlattice is coupled with an m -layered [Fe/Cr](m) ferromagnetic (F) superlattice, to provide a controlled exchange bias. In low magnetic fields, the magnetizations of the two super lattices are collinear. The two magnetized states (along or opposite to the bias field) differ only in the relative orientation of the F and adjacent AF layer. At higher fields, the AF moments flop to the direction perpendicu lar to the applied field. The structure, thus determined, explains the magn itude of the bias field. (C) 1999 American Institute of Physics. [S0003-695 1(99)03052-1].