Low frequency plasmonic (LFP) state induced by the electrical percolation of metallic particles has been investigated for metal granular composite materials containing Cu, Ni47Fe53 and Co50Fe50 microparticles. In these composites, a conductivity jump due to electrical percolation takes place at different particle volume fraction j; a conductive state is established above the percolation threshold jC. The jC is 0.16 for Cu, 0.61 for Ni47Fe53, and 0.76 for Co50Fe50 composites, respectively. In the Cu composite, the LFP state takes place in the conductive state just above jC. However, in the Ni47Fe53 composite, the LFP state is established at j = 0.90; the LFP state couldn’t be observed in the Co50Fe50 one. Hence, a non-plasmonic conductive state can exist in the percolated state; the LFP state can be established in the conductive state with about 1.0 S/cm of the conductivity value. 

Graphical Abstract

Percolation-induced low frequency plasmonic state in metal granular composite materials