FERROMAGNETIC-RESONANCE IN COUPLED PERMALLOY DOUBLE FILMS SEPARATED BY A CU INTERLAYER

Ferromagnetic resonance (FMR) at 16 GHz was used to study the magnetic coupling between two-layers of permalloy separated by a nonmagnetic Cu layer. Samples with the same thickness (600 angstrom) of both permalloy layers were deposited from e-gun sources onto glass substrates in UHV. The thickness d of the Cu interlayer was varied from 5 to 37 angstrom. The exchange coupling energy (E = -KM1.M2) model was used to describe the interaction between the two magnetic layers. It was found from the ferromagnetic resonance data in the perpendicular configuration that K(d) follows an exponential law, K = K0e-d/q, where q = 9.3 angstrom.