Interface formation and magnetic ordering in Fe/Cr hybrid nanostructures

Hybrid magnetic nanostructures prepared from ultrathin 57Fe layers alternating with thick Cr layers were studied by using polarized neutron reflectometry. It was shown that the sample with Fe layer thickness t=2Å remains in superparamagnetic state at room temperature. Increasing the Fe-thickness to t=4Å leads to crossover between superparamagnetic and ferromagnetic spin-glass Fe states and non-zero mean magnetic moment in Fe layers appears.