Unusual interlayer-coupling effect in Fe-Si/Cr multilayered films

Fe-Si/Cr multilayered films with amorphous magnetic Fe-Si layers have been prepared with the rf-sputtering method at different Ar charging pressures. Samples with antiferromagnetic exchange coupling can be obtained only at a higher Ar charging pressure, ${\mathit{P}}_{\mathrm{Ar}}$. When ${\mathit{P}}_{\mathrm{Ar}}$=5 mTorr and the Fe-Si layers are as thin as 19 \AA{}, an oscillatory function of magnetization versus the thickness of Cr layers with a period of about 10 \AA{} is obtained. This is an effect specific to interlayer coupling in the multilayered films, and is caused by oscillatory changes of the internal field in Fe-Si layers.