Tailorable epsilon-negative and epsilon-near-zero behavior of TiC/CCTO metacomposites: Low-frequency plasma oscillation

Abstract

Epsilon-negative ([Formula: see text] < 0) and epsilon-near-zero (ENZ) property was demonstrated in titanium carbide/copper calcium titanate (TiC/CCTO) metacomposites. Benefiting from the moderate concentration of free electrons in TiC filler and its adjustable three-dimensional (3D) networks, weakly negative permittivity ([Formula: see text]200 at 20 MHz) was achieved. Not only that, tailoring the negative permittivity of metacomposites from [Formula: see text]200 to [Formula: see text]2060, [Formula: see text]4200, [Formula: see text]14000 and [Formula: see text]70000 at 20 MHz was realized by simply increasing TiC content. Besides, Drude model was used to explain the radio-frequency (RF) negative permittivity and quantified the collective plasma oscillation in TiC networks.