For amorphous-FeNiB (2.0 nm)/Ru multilayers, an oscillatory interlayer coupling is observed with the variation of the Ru spacer thickness. At 0.8 nm thick Ru layer, near the first antiferromagnetic coupling maximum, the energy of the effective interlayer coupling at low temperature T is found to change as a linear function of T: At the same time, the spontaneous magnetization of the samples at ...
