Nanostructures based on Gd/MgO/Fe superlattices are an artificial ferromagnetic material in which the exchange interaction of the magnetic moments of Fe layers through intermediate dielectric and rare-earth layers can lead to magnetic configurations that are not realized in the well-studied Fe/Cr systems and Fe/MgO/Fe. In this work, we investigated the complex structural and magnetic properties of a series of superlattices Nb(20 nm)/[Gd(5 nm)/MgO(t nm)/Fe(5 nm)]х6/Nb(5 nm) with different thicknesses of MgO dielectric layers (t = 0, 0.4, 0.8, and 1.2 nm). High-resolution X-ray reflectometry data confirmed the formation of a layered structure of superlattices with layer thicknesses close to nominal and sharp interlayer boundaries. Vibration magnetometry revealed a difference in the hysteresis loops of a sample without MgO layer and samples in which MgO layers of different thicknesses were present. A sample with zero thickness of the dielectric layers has a significantly lower saturation magnetization.