Brillouin light scattering study of an exchange coupled asymmetric trilayer of Fe/Cr

The magnetic response of a (211) oriented asymmetric Fe trilayer [Fe(100 An gstrom)/Cr(9 Angstrom)/Fe(20 Angstrom)/Cr(20 Angstrom)/Fe(20 Angstrom)], in which the thickness of the Cr spacer layers was chosen to produce ferromag netic coupling (F) between the two thinner Fe layers and antiferromagnetic coupling (AF) between the thicker Fe layer and the adjacent thin one, has b een investigated using magnetization and Brillouin light scattering (BLS) m easurements. The coupling coefficients, extracted by fitting the BLS and ma gnetization measurements with a theory treating the static and dynamic resp onse on an equal footing? produced consistent values of the magnetic parame ters. Our results confirm that the theoretical model used in interpreting b oth static and dynamic properties is valid even in systems in which F and A F coupling of the layers are simultaneously present. The theoretical model has also been extended to include the field dependence of the intensity of the Brillouin peaks. The calculated intensities are compared with the BLS s pectra at different applied fields. (C) 2000 Elsevier Science B.V. All righ ts reserved.