Anomalous microwave absorption in multi-walled carbon nanotubes filled with iron

The interaction of millimeter-wave radiation (MWR) with vertically oriented carbon nanotubes filled with iron (Fe-MWCNT) in solid monolith has been investigated. Fe-MWCNT demonstrated high-efficiency towards electromagnetic shielding due to a high conductivity of CNT and iron-containing filling compound. The shielding efficiency and the reflection loss depending on the CNT orientation have been measured in a rectangular waveguide. A resonant absorption of millimeter waves has been revealed with the orthogonal Fe-MWCNT orientation with respect to the MWR electric field in the waveguide.