Reflection of millimeter waves from a waveguide containing Fe/Cr superlattices

The basic mechanism of interaction between electromagnetic waves and superlattices is microwave analog of a giant magnetoresistance as has been shown in our experiments. There were observed both negative and positive reflectivity relative changes. Their absolute values are more than maximum GMR measured on dc for relevant samples and achieve at least 50%. The shape of the magnetic field dependencies of the relative variation reflection coefficient is similar to the dc magnetoresistance curves. These dependencies for the cases parallel and perpendicular pumping are different from each other only its absolute values. Their signs are the same and shapes are similar for respective superlattices and frequencies.