Spin Density Wave Instability for Chromium in Fe/Cr(100) Multilayers

Using perturbed angular correlation spectroscopy on Fe $/$Cr epitaxially grown multilayers, we observed an in-plane magnetization for Fe layers (thickness between 1.5 and 38 nm), while Cr (thickness between 7.5 and 40 nm) orders antiferromagnetically as a longitudinal (A${\mathrm{F}}_2$) spin density wave with the magnetization along the (100) direction normal to the layers, persisting well above the Néel temperature of bulk chromium. The Cr layers lose the Cr bulk magnetism and become paramagnetic, down to 4.2 K, or even nonmagnetic for thickness below 6.0 nm.