Magnetic-field-induced spin reorientations in magnetic superlattice structures: Explicit examples

Superlattice structures may exhibit unique properties, distinctly different from those of the individual constituents from which the structure is synthesized. We illustrate this by exploring some properties of model superlattices fabricated from a ferromagnet and an antiferromagnet, the latter with sheets of ferromagnetically aligned spins each parallel to the interface. We find magnetic-field-induced spin reorientation transitions in such a structure. These may be viewed as the antiferromagnetic spin flop transition, modified by the presence of the intervening ferromagnetic layers. For the case where the anitferromagnetic constituent contains an even number of spin sheets, the spin flop field can be very much lower than that realized in the isolated antiferromagnet.