Ferromagnetic resonance study of magnetic phases in FeNi∕Al∕FeMn∕Al and FeMn∕Al∕FeNi∕Al multilayers

Abstract

A comparative ferromagnetic resonance (FMR) study of the magnetic properties of Si(100)[FeNi∕Al∕FeMn∕Al]×10 and Si(100)[FeMn∕Al(6Å)∕FeNi(30Å)∕Al]×20 multilayers is reported. Besides the uniform mode, the parallel and perpendicular FMR spectra of both multilayers also give evidence of additional magnetic phases in the films. The perpendicular FMR spectrum of the first multilayer also shows the presence of a volume spin-wave resonance (SWR) mode, while the spectrum of the second shows the presence of a surface SWR mode. This is attributed to the structural differences between the two multilayers in terms of the thicknesses of the magnetic (FeNi) and nonmagnetic (FeMn and Al) layers.