Polarization of Pd atoms and interlayer coupling in Fe-Si/Pd multilayers

In this paper two series of Fe-Si/Pd multilayers are made by rf sputtering and studied by vibrating sample magnetometry and electronic paramagnetic resonance spectroscopy. For Fe-Si/Pd (5.4 nm) multilayers with increasing Fe-Si layer thickness, the saturation magnetization M(s), decreases. This is an evidence of the spin-polarization of Pd atoms. An interlayer coupling is confirmed to exist by spin wave modes in Fe-Si (1.5 nm)/Pd multilayers with Pd layer thickness d(Pd) less than or equal to 7.2 nm; except for d(Pd) = 1.8 nm. For d(Pd) = 1.8 nm no interlayer coupling occurs, and both the saturation magnetization M(s), and the effective magnetization 4 pi M(eff) have a minimum. The resonance linewidth Delta H changes correspondingly with the effective magnetization as a function of d(Pd) and has a maximum at d(Pd) of 1.8 nm.