Standing spinwaves in femn/nife/femn exchange-bias structures

34 GHz ferromagnetic resonance (FMR) measurements of sputtered FeMn/NiFe/FeMn thin films show sinusoidal azimuthal variation of both resonance fields and amplitudes of low and high order spinwaves. Analysis of mode spectra yields an average unidirectional exchange coupling constant Ks=-1.0 erg/cm2. FMR linewidth varies linearly with inverse thickness, indicating a random in-plane distribution in local Ks values, with a width of 0.2 erg/cm2. Similar dispersive components normal to the interface are also found. The magnitude of local Ks is comparable to the average over the interface. The thickness of the interfacial transition region is much less than 25A. © 1987 IEEE