Brillouin light scattering study of Co/Cr/Co trilayers

Spin-wave excitations have been observed in Co(212 Å)/Cr(d0)/Co(200 Å)/Si trilayers for 5 < d0 < 35 Å. Two modes, symmetric and antisymmetric, showed a frequency variation with applied in-plane magnetic field (0.1 < H < 5.0 kOe). The small frequency changes with Cr thickness at high and low fields indicate that exchange coupling is small. Values of 4πMs typical of bulk values were obtained from fits to theory. No in-plane orientational frequency dependence was observed.