Synthesis and investigation of random metal-dielectric as microwave metamaterials

Metal-dielectric nanocomposites made of Ag nanorods embedded in Co0.05Ti0.95O2 were investigated. The effect of Ag contents on dielectric and magnetic responses of nanocomposites was studied. The results show that above the percolation threshold, the nanocomposite has metal-like behavior with negative permittivity. Moreover, the combined contributions of the magnetic resonance of ferrimagnetic Co0.05Ti0.95O2 particles and the diamagnetic response of the current loops (made of random Ag nanorod networks) bring about negative permeability in high frequency. These results indicate that the CTO-Ag 30% sample is a promising candidate for the double-negative materials