Dual-band metacomposites containing hybrid Fe and Co-based ferromagnetic   microwires
  We investigated the microwave properties of polymer based metacomposites containing hybridized parallel Fe- and Co-based microwire arrays. A dual-band left-handed feature was observed in the frequency bands of 1.5 to 5.5 GHz and 9 to 17 GHz, indicated by two transmission windows associated with ferromagnetic resonance of Fe-based microwires and long range dipolar resonance between the wire arrays. The plasma frequency after hybridization is significantly increased due to the enhanced effective diameter through the wire-wire interactions between the Fe- and Co- microwire couples. These results offer essential perspectives in designing the multi-band metamaterial for microwave applications such as sensors and cloaking devices. 
Y. Luo, H.X. Peng, F.X. Qin, M. Ipatov, V. Zhukova, A. Zhukov and J.   Gonzalez
cond-mat.mtrl-sci