Magnons in antiferromagnetically coupled superlattices

We present an experimental Brillouin-scattering study of the collective spin-wave modes in antiferromagnetically coupled Fe/Cr(211) superlattices. We show spectra as a function of external magnetic field, where the field is swept from very small values up to those required to saturate the sample in the ferromagnetic state. We thus explore excitations in the low-field antiferromagnetic state, the surface spin-flop regime, the symmetric open-quote open-quote bulk close-quote close-quote spin-flop regime, and the high-field state. The data are compared with theoretical studies based on a description of the collective modes developed previously. copyright 1996 The American Physical Society