A calculation of spin-wave propagation through a nearly nonmagnetic film sandwiched between two magnetic films is given as a function of the thickness of the nonmagnetic film and of a parameter that describes the decay of the exchange through this film and can be related to structural features such as interface roughness or spin-polarization penetration depth. The comparison with experiment enables us to determine this exchange decay parameter for a series of experiments in Permalloy-copper-Permalloy sandwiches prepared in an UHV system.

• Received 8 October 1990

DOI:https://doi.org/10.1103/PhysRevB.43.3311