Communication—Dielectric Dispersion of Chromium Carbide/Copper Calcium Titanate Metacomposites: Epsilon-Negative, Epsilon-Near-Zero, and Inductive Character

Abstract

Chromium carbide/copper calcium titanate (Cr3C2/CCTO) metacomposites were fabricated, wherein epsilon-negative and epsilon-near-zero (ENZ) properties were simultaneously obtained. When Cr3C2 content exceeds percolation threshold, the formation of Cr3C2 networks triggers a well-pronounced epsilon-negative behavior. The epsilon-negative property originates from low-frequency plasma oscillation which mainly correlates with concentration of free electrons in Cr3C2 networks. Epsilon-negative is remarkably achieved at absolutely weak value (∼−102) at 30 wt% content of Cr3C2, and negative permittivity was tuned to ∼−103 by increasing Cr3C2 content. Transition of permittivity from positive to negative was accompanied by electrical character changing from capacitive to inductive.