Preparation and properties of a left-handed metamaterial composite

A left-handed metamaterial (a YIG/Ag composite with adjustable negative permittivity and permeability) was prepared by an in situ synthesis process, and its characterisation, microstructure, electrical conductivity, dielectric loss and magnetic properties studied. A negative permittivity behaviour with a Fano-like resonance is ascribed to plasma oscillation of delocalised electrons from silver conducting networks. As the silver content increases, the turbine loss increases, which greatly enhances the electromagnetic wave consumption capacity inside the material and leads to a stronger electromagnetic absorption and shielding performance. The dielectric loss near the percolation threshold is due to the combined effects of polarisation and conduction. The capacitive character is responsible for positive permittivity, and the inductive character leads to negative permittivity. LC resonance results in the Fano-like resonance, leading to the permittivity changing from negative to positive. Gyromagnetic spin rotation, domain wall motion and percolation characteristic of YIG/Ag composites cause frequency dispersion of the permeability. The YIG/Ag composite with double negative characteristics provides prospects for electromagnetic shielding application.