High-frequency properties of Fe/Cr superlattices with thin Cr layers in the millimeter-wavelength range

Microwave properties of Fe/Cr multilayer nanostructures with thin chromium layers (with thickness $t_{\mathrm{Cr}}<$ 1 nm) are analyzed. Experiments are performed by the method of penetration of microwaves in the frequency range from 26 to 38 GHz. The dependence of the transmission coefficient for microwaves on the constant magnetic field strength exhibits the microwave magnetoresistive effect and magnetic resonance. The resonance spectrum is reconstructed from measurements at various frequencies. The results of microwave measurements are analyzed together with the results of magnetic and magnetoresistive measurements.